The present invention relates to furanone derivatives, particularly to derivatives having cytoprotective activity, especially certain 3-hydroxy-furan-2-one derivatives. The invention is also directed to formulations and methods for treating stroke, myocardial infarction and chronic heart failure, as well as other oxidative stress-related conditions that are typically responsive to cellular enzyme modulation. The invention is also directed to formulations and methods for treating neuroinflammation, cognitive disorders and neurodegenerative diseases such as Alzheimer""s disease and senile dementia.
The present invention deals with certain novel furanone derivatives, which are formed under proper conditions from a series of pyruvate derivatives described in our prior applications, U.S. Ser. No. 10/138,937 and 10/138,032.
Furanones are compounds having the following general structure. 
Furanone-derived compositions have been known in the art to have various utilities. For example, U.S. Pat. No. 6,296,889 describes the use of certain furanone compounds in conjunction with 1-nonen-3-one to provide dairy and coffee aroma flavor enhancement. Specific furanones (for example, 3,-(3,4-difluorophenyl)-4-(4-(methylsulfonyl)phenyl)-2-(5H)-furanone, 3-phenyl-4-(4-(methylsulfonyl)phenyl)-2-(5H)-furanone and 5,5-dimethyl-4-(4-(methylsulfonyl)phenyl)-3-(3-fluorophenyl)-5H-furan-2-one) have been shown to be cyclooxygenase-2 (COX-2) inhibitors useful in treating certain inflammatory conditions (U.S. Pat. No. 5,474,995, U.S. Pat. No. 6,239,173). The diversity of furanone derivative utilities is further illustrated by the discovery of certain halogenated furanones isolated from the Australian red seaweed Delisea nulcha as marine anti-fouling agents (U.S. Pat. No. 6,060,046) capable of preventing growth of various seaweeds, invertebrates and bacteria on marine structures. The furanone derivative 4-hydroxy-3-methanesulfonyl-2-methanesulfonylmethyl-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester (CAS Registry No. 299923-61-8) is available for screening from the compound library of InterBioScreen Ltd. (Moscow, Russiaxe2x80x94www.ibscreen.com), among other sources.
The synthesis of the compound 4-hydroxy-3-isobutyl-2-(3-methyl-butyryl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid methyl ester has been described in Trogolo, C. et al Annali di Chimica 62(10), 674-92, (1972) and the synthesis of 4-hydroxy-5-oxo-2,3-dipentyl-2,5-dihydro-furan-2-carboxylic ethyl ester has been described in Hoffman, R. V. et al. Journal of Organic Chemistry, 62(8)2458-2465, (1997). The synthesis of certain furanones derivatives from hydroxy alkanoates is described in Stach, H., Helvetica Chimica Acta (1987), 70(2), 369-74.
Cerebral ischemia or xe2x80x9cstrokexe2x80x9d refers to the severe diminution or cessation of blood flow to all or part of the brain. Cerebral ischemia can occur as a result of a number of causes or insults, including, but not limited to cerebrovascular occlusion, thromboembolytic insult, cardiac failure and hemorrhagic accident. It is now known that pharmacologic intervention, if provided within a reasonable interval of the initial insult, can significantly reduce cerebral tissue death following cerebral ischemia.
Alzheimer""s Disease (xe2x80x9cADxe2x80x9d) is a progressive disease of the human central nervous system. It is manifested by dementia in the elderly, by disorientation, loss of memory, difficulty with language, calculation, or visual-spatial skills, and by psychiatric manifestations. It is associated with degenerating neurons in several regions of the brain. Alzheimer""s Disease is reviewed by Price, D. L. et al. (Clin. Neuropharm. 14:S9-S14 (1991)); Pollwein, P. et al. (Nucl. Acids Res. 20:63-68 (1992)); Regland, B. et (Med. Hypoth. 38:11-19 (1992)) and Johnson, S. A. (In: Review of Biological Research in Aging, Vol. 4., Rothstein, M. (Ed.), Wiley-Liss, NY, 163-170 (1990)).
The present invention addresses the desire to provide new therapies for conditions characterized by oxidative stress and/or inflammation, and particularly, for providing neuroprotection in the event of cerebral ischemia; especially desired are agents that are effective even if first administered after a significant period of time (e.g., about 5 or more hours) following an ischemic insult. The present invention also addresses the desire to provide new therapies for conditions characterized by neuroinflammation, cognitive disorders, and/or neurodegenerative conditions such as Alzheimer""s and senile dementia.
The present invention is concerned with novel furanone derivatives that are particularly active in restoring or preserving metabolic integrity in oxidatively competent cells that have been subjected to oxygen deprivation. Such furanone derivatives are useful in the manufacture of pharmaceutical compositions for treating a number of conditions characterized by oxidative stress, and particularly, in providing neuroprotection in the event of cerebral ischemia, even when administered a significant time interval after an ischemic insult. In particular, the compositions of the present invention are useful in the treatment of stroke, as demonstrated by providing neuroprotection in a standard experimental model of focal cerebral ischemia. They are also useful in the treatment of neuroinflammation, cognitive disorders and neurodegenerative diseases such as neuropathy in cerebrovascular diseases, brain trauma, cerebral palsy, epilepsy, amyotrophic lateral sclerosis (ALS), Huntington""s disease, mental diseases (e.g. psychosis, schizophrenia, depression), Parkinson""s disease, Friedreich""s disease, Down""s syndrome, Creutzfelt-Jakob syndrome, Alzheimer""s disease, and senile dementia.
They are also useful in the treatment of myocardial ischemia (myocardial infarction), as well as other indications characterized by oxidative stress and/or inflammation, including, but not limited to, diabetes, renal disease, pre-menstrual syndrome, asthma, cardiopulmonary inflammatory disorders, chronic heart failure, rheumatoid arthritis, muscle fatigue, intermittent claudication and for the preservation of allograft tissue for transplantation.
The present invention concerns the compounds represented by the formula: 
wherein:
R1 is: xe2x80x94C(O)ORxe2x80x2; xe2x80x94C(O)NRxe2x80x2Rxe2x80x3; xe2x80x94CH2ORxe2x80x2xe2x80x3; cyano; optionally substituted heterocyclyl; optionally substituted heterocyclyl-alkyl; optionally substituted heteroaryl, or optionally substituted heteroaralkyl;
R2 is: optionally substituted alkyl; optionally substituted cycloalkyl; optionally substituted aryl; optionally substituted aralkyl; optionally substituted heterocyclyl, optionally substituted heteroaryl; optionally substituted heteroaralkyl; an optionally substituted nucleoside; an optionally substituted amino acid; or an optionally substituted di-, tri- or tetra-peptide;
R3 is: optionally substituted alkyl; optionally substituted cycloalkyl; optionally substituted aryl; optionally substituted aralkyl; optionally substituted heterocyclyl, optionally substituted heteroaryl; optionally substituted heteroaralkyl; an optionally substituted nucleoside; an optionally substituted amino acid; or an optionally substituted di-, tri- or tetra-peptide;
R4 is: hydrogen; alkyl, alkylcarbonyl; (poly)alkoxyalkylene; or dialkoxyphosphoryloxy (or other moieties readily hydrolyzable to give an OH moiety);
X is: lower alkylene; xe2x80x94N(Rxe2x80x2)xe2x80x94; xe2x80x94Sxe2x80x94; xe2x80x94S(O)xe2x80x94; xe2x80x94S(O)2xe2x80x94, or X taken together with R2 is xe2x80x94P(O)(ORxe2x80x2)2;
Y is: xe2x80x94N(Rxe2x80x2)xe2x80x94; xe2x80x94Sxe2x80x94; xe2x80x94S(O)xe2x80x94; xe2x80x94S(O)2xe2x80x94, or Y taken together with R3 is xe2x80x94P(O)(ORxe2x80x2)2;
or Xxe2x80x94R2 taken together with Yxe2x80x94R3 form an optionally substituted aliphatic or aromatic ring,
Rxe2x80x2 is: hydrogen; alkenyl; optionally substituted alkyl; optionally substituted cycloalkyl; phosphoryl; or optionally substituted aryl;
Rxe2x80x3 is: hydrogen, alkenyl, optionally substituted alkyl, or optionally substituted aryl;
or Rxe2x80x2 and Rxe2x80x3 together with the atom to which they are attached form a 5- to 7-membered aromatic, saturated or unsaturated ring, optionally incorporating one or more additional heteroatom chosen from N, O, or S, and optionally substituted with one or more substituents selected from the group consisting of optionally substituted lower alkyl, halo, cyano, alkylthio, lower alkoxy, carboxy, benzyl, and oxo; and
Rxe2x80x2xe2x80x3 is: hydrogen; alkenyl; optionally substituted alkyl; optionally substituted cycloalkyl; acyl; phosphoryl; or optionally substituted aryl;
including single tautomers, single stereoisomers and mixtures of tautomers and/or stereoisomers, and the pharmaceutically acceptable salts thereof.
In one embodiment R4 is hydrogen, (C1 to C8)alkyl, or (C1 to C8)alkylcarbonyl.
In another embodiment where R2 and/or R3 is a natural or substituted amino acid or peptide, R2 and/or R3 is selected from the group: Ala, Asn, Asp, Cys, Gin, Glu, Gly, Lys, Met, Ser and Thr, especially Ala, Asp, Cys, Glu and Gly. Further preferred are those compounds where R2 and/or R3 is a natural or substituted di- or tri-peptide, especially natural peptides.
In yet another embodiment, R2 and/or R3 is/are an optionally substituted heteroaryl or heteroaralkyl group, especially a nitrogen-containing optionally substituted heteroaryl, and particularly selected from the group: imidazole, pyrazole, triazole, thiadiazole, oxadiazole, benzoimidazole, benzooxazole, benzoselenazol, and benzothiazole, or an optionally substituted heteroaralkyl group, particularly an optionally substituted furanyl-loweralkyl group.
In yet another embodiment, R2 and/or R3 is/are an optionally substituted alkyl or optionally substituted cycloalkyl.
In another embodiment embodiment, R2 and/or R3 is/are an optionally substituted aryl or optionally substituted aralkyl, preferably optionally substituted phenyl or benzyl.
Further preferred in each of the foregoing embodiments, R1 is xe2x80x94C(O)ORxe2x80x2, xe2x80x94CH2ORxe2x80x2xe2x80x3 or xe2x80x94C(O)NRxe2x80x2Rxe2x80x3; and Rxe2x80x2, Rxe2x80x3, and Rxe2x80x2xe2x80x3 are hydrogen or lower alkyl (C1 to C8), and especially R1 is xe2x80x94C(O)ORxe2x80x2, and R is hydrogen or (C1 to C8)alkyl.
Presently preferred for the pharmaceutically acceptable salts of the invention are the TEA, TFA, HCl, HBr, MsOH, TsOH, AcOH, and Na salts of the furanone compounds of the present invention.
Further preferred in each of the foregoing embodiments are those compounds where X and Y are the same particularly xe2x80x94Sxe2x80x94, xe2x80x94S(O)xe2x80x94 or xe2x80x94S(O)2xe2x80x94, preferably xe2x80x94Sxe2x80x94; and especially those where xe2x80x94Xxe2x80x94R2 and xe2x80x94Yxe2x80x94R3 are the same.
Another embodiment of the invention concerns compounds according to Formula I where Xxe2x80x94R2 and/or Yxe2x80x94R3 is/are represented by the formula: 
where:
R2.1 is: hydrogen, optionally substituted alkyl, optionally substituted aryl, xe2x80x94C(O)xe2x80x94Oxe2x80x94R2xe2x80x2, xe2x80x94Sxe2x80x94, or xe2x80x94CH2xe2x80x94Sxe2x80x94;
R2.2 is: hydrogen, optionally substituted alkyl, optionally substituted aryl, optionally substituted aralkyl, or optionally substituted acyl (particularly including aliphatic, aromatic and cyclic acyl substituents);
R2.3 is: hydrogen, optionally substituted lower alkyl, optionally substituted aralkyl, optionally substituted heteroaralkyl, or xe2x80x94CH2xe2x80x94Sxe2x80x94 (selected independently, in each occurrence of R2.3);
R2.4 is: hydrogen, optionally substituted lower alkyl, optionally substituted aralkyl, optionally substituted heteroaralkyl, or xe2x80x94CH2xe2x80x94Sxe2x80x94;
R2.5 is: hydrogen, optionally substituted alkyl or optionally substituted aryl;
R2xe2x80x2 is: hydrogen, optionally substituted alkyl, or optionally substituted aryl (selected independently, in each occurrence of R2xe2x80x2);
k is: 0, 1 or 2;
m is: 0, 1 or 2; and
n is: 0, 1, 2 or 3,
at least one of R2.1, R2.3 and R2.4 being xe2x80x94CH2xe2x80x94Sxe2x80x94.
Of the compounds where Xxe2x80x94R2 and/or Yxe2x80x94R3 are represented by Formula II, preferred are those compounds the substituents of which are selected from the following groups:
R2.1 is xe2x80x94C(O)xe2x80x94Oxe2x80x94R2xe2x80x2 where R2xe2x80x2 is hydrogen or lower alkyl, especially ethyl;
R2.2 is hydrogen;
R2.3 is xe2x80x94CH2xe2x80x94Sxe2x80x94;
R2.4 is hydrogen, optionally substituted lower alkyl, optionally substituted aralkyl, optionally substituted heteroaralkyl;
R2.5 is hydrogen or lower alkyl, especially hydrogen; and/or
k, m and n are respectively: 0,2,1; 1,0,1; or 2,0,1.
Another aspect of this invention concerns the compounds represented by the formula: 
wherein:
R5 is: xe2x80x94C(O)ORa; xe2x80x94C(O)NRaRb; xe2x80x94CH2ORd; xe2x80x94C(O)Rc; cyano; optionally substituted heterocyclyl, or optionally substituted heteroaryl;
R6 is hydrogen; xe2x80x94C(O)ORa; xe2x80x94C(O)NRaRb; xe2x80x94CH2ORd; xe2x80x94C(O)Rc; cyano; optionally substituted alkyl; optionally substituted heterocyclyl; optionally substituted aryl; or optionally substituted heteroaryl;
or R5 and R6 with the atom to which they are attached form an optionally substituted ring;
R7 is: optionally substituted alkyl; optionally substituted cycloalkyl; optionally substituted aryl; optionally substituted aralkyl; optionally substituted heterocyclyl, optionally substituted heteroaryl; optionally substituted heteroaralkyl; an optionally substituted nucleoside; an optionally substituted amino acid; or an optionally substituted di-, tri- or tetra-peptide; with the proviso that when R6 is alkyl, then R7 is optionally substituted heterocyclyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.
or R5 and R7 with the atoms to which they are attached form an optionally substituted heterocyclic ring;
R8 is: hydrogen; alkyl, alkylcarbonyl; (poly)alkoxyalkylene; or dialkoxyphosphoryloxy;
Yxe2x80x2 is: xe2x80x94N(Ra)xe2x80x94; xe2x80x94Sxe2x80x94; xe2x80x94S(O)xe2x80x94; or xe2x80x94S(O)2xe2x80x94;
Ra is: hydrogen; alkenyl; optionally substituted alkyl; optionally substituted cycloalkyl; or optionally substituted aryl;
Rb is: hydrogen; alkenyl; optionally substituted alkyl; alkyl ether; or optionally substituted aryl;
or Ra and Rb together with the atom to which they are attached form a 5- to 7-membered aromatic, saturated or unsaturated ring, optionally incorporating one more additional heteroatom chosen from N, O, or S, and optionally substituted with one or more substituents selected from the group consisting of optionally substituted lower alkyl, halo, cyano, alkylthio, lower alkoxy, carboxy, benzyl, and oxo;
Rc is optionally substituted alkyl or optionally substituted aryl; and
Rd is hydrogen; alkenyl; optionally substituted alkyl; acyl, optionally substituted cycloalkyl; or optionally substituted aryl;
including single tautomers, single stereoisomers and mixtures of tautomers and/or stereoisomers, and the pharmaceutically acceptable salts thereof.
In another embodiment, R7 is an optionally substituted heteroaryl group, especially a nitrogen-containing optionally substituted heteroaryl, and particularly selected from the group: imidazole; pyrazole; triazole; thiadiazole; oxadiazole; benzoimidazole; benzooxazole; benzoselenazole and benzothiazole.
In another embodiment R5 is xe2x80x94C(O)ORa or xe2x80x94C(O)Rc; Ra is hydrogen, (C1-C8)alkyl, or (C3-C8)cycloalkyl; and Rc is lower alkyl or aryl.
In another embodiment R5 is heteroaryl and R6 is hydrogen.
In another preferred embodiment R6 is hydrogen or xe2x80x94C(O)ORa; and Ra is hydrogen or lower alkyl (C1 to C8).
In another preferred embodiment R5 and R6 form a ring, particularly a pyrimidine-2,4,6-trione ring or a cyclohexanone ring.
In another preferred embodiment R5 and R7 form a ring, particularly when R7 is benzoimidazole, the ring is 3-methyl-thiomorpholin-3-ol and the compound formed is 1,4-dihydro-4-methyl-3a,4-dihydro-3-oxa-10-thia-4a,9-diaza-cyclopenta[b]fluoren-2-one.
In another preferred embodiment R8 is hydrogen.
Further preferred in each of the foregoing embodiments are those compounds where R5 is xe2x80x94C(O)ORa or xe2x80x94C(O)Rc, R6 is hydrogen, and Yxe2x80x2 is xe2x80x94Sxe2x80x94.
In another aspect the invention relates to compounds of Formula I or Formula III forming a complex with a metal, especially when said metal is selected from divalent copper, manganese, or zinc, particularly wherein said metals are selected from Cu2+Cl2, Mn2+Cl2, and Zn2+Cl2.
In another aspect, the invention relates to a pharmaceutical composition containing a therapeutically effective amount of a compound of Formula I or Formula III, or a pharmaceutically acceptable salt thereof admixed with at least one pharmaceutically acceptable excipient. Particularly preferred are those pharmaceutical compositions wherein the compound of Formula I or Formula III is selected from the preferred compounds.
In still another aspect, the invention relates to a method of treating stroke and/or other oxidative stress-related conditions that are responsive to cellular enzyme modulation such as cerebral ischemia, myocardial infarction and chronic heart failure (especially stroke/cerebral ischemia) in a mammal by administering to a mammal in need of such treatment a therapeutically effective amount of a compound of Formula I or Formula III or a pharmaceutically acceptable salt thereof. Particularly preferred are those methods of treatment and uses in the manufacture of pharmaceutical compositions therefor, wherein the compound of Formula I or Formula III is selected from the preferred compounds, and especially from the compounds selected from:
3-(Benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid (2-hydroxy-ethyl)-amide;
3-(2,4-Dichloro-benzylsulfanyl)-2-(2,4-dichloro-benzylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(5-Amino-[1,3,4]thiadiazol-2-ylsulfanyl)-2-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
4-(2,2-Dimethyl-propionyloxy)-3-(furan-2-ylmethylsulfanyl)-2-(furan-2-ylmethylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzooxazol-2-ylsulfanyl)-2-(benzooxazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
4-Hydroxy-5-oxo-3-(pyrrolidine-1-carbothioylsulfanyl)-2-(pyrrolidine-1-carbothioylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Cyclohexylsulfanyl-2-cyclohexylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(pyridin-4-ylsulfanyl)-2-(pyridin-4-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(5-phenyl-[1,3,4]oxadiazol-2-ylsulfanyl)-2-(5-phenyl-[1,3,4]oxadiazol-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester; and
3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
In a preferred embodiment the invention relates to methods of treating a condition selected from stroke, cerebral ischemia, retinal ischemia, post-surgical cognitive dysfunctions, peripheral neuropathy/neuropathic pain, spinal cord injury, head injury and surgical trauma.
In another preferred embodiment the invention relates to methods of treating a condition involving inflammatory or automimmune components, especially diseases including but not limited to diabetes, renal disease, premenstrual syndrome, asthma, rheumatoid arthritis, osteoarthritis, muscle fatigue, irritable bowel syndrome, inflammatory bowel disease, and intermittent claudication. Particularly preferred are those methods of treatment and uses in the manufacture of pharmaceutica compositions therfor, wherein the compound is selected from the preferred compounds, and especially from the compounds selected from;
3-(Benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(5-phenyl-2H-[1,2,4]triazol-3-ylsulfanyl)-2-(5-phenyl-2H-[1,2,4]triazol-3-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-(1H-Benzoimidazol-2-ylsulfanyl)-5-(1H-benzoimidazol-2-ylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
4-Hydroxy-5-oxo-3-(4-trifluoromethyl-pyrimidin-2-ylsulfanyl)-2-(4-trifluoromethyl-pyrimidin-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(pyrimidin-2-ylsulfanyl)-2-(pyrimidin-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(2-sulfo-ethylsulfanyl)-2-(2-sulfo-ethylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(7-trifluoromethyl-quinolin-4-ylsulfanyl)-2-(7-trifluoromethyl-quinolin-4-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzoselenazol-2-ylsulfanyl)-2-(benzoselenazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(5-sulfonic acid-1H-benzoimidazol-2-ylsulfanyl)-2-(5-sulfonic acid-1H-benzoimidazol-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
4-Hydroxy-5-oxo-3-(pyrrolidine-1-carbothioylsulfanyl)-2-(pyrrolidine-1-carbothioylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Cyclohexylsufanyl-2-cyclohexylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(2-Dimethylamino-ethylsulfanyl)-2-(2-dimethylamino-ethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester, hydrochloride salt;
4-Hydroxy-5-oxo-3-(pyridin-4-ylsulfanyl)-2-(pyridin-4-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
5,8-Dichloro-3-hydroxy-2-oxo-2H-1-oxa-4,9-dithia-benzo[f]azulene-10a-carboxylic acid ethyl ester;
3-(5-Chloro-benzothiazol-2-ylsulfanyl)-2-(5-chloro-benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester; and
3-(5-Amino-[1,3,4]thiadiazol-2-ylsulfanyl)-2-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
Another group of diseases characterized by oxidative stress fall within the group dermatologic conditions, including, but not limited to prevention and protecting skin tissue against age-related damage or damage resulting from insults such as harmful ultraviolet (UV) radiation, stress and fatigue, and in the treatment of contact dermatitis, skin irritation, skin pigmentation, psoriasis, or acne.
In still another aspect, the invention relates to a method of treating neuroinflammation, cognitive disorders, and/or neurodegenerative disorders in a mammal by administering to a mammal in need of such treatment a therapeutically effective amount of a compound of Formula I or Formula III, or a pharmaceutically acceptable salt thereof. Particularly preferred are those methods of treatment and uses in the manufacture of pharmaceutical compositions therefor, wherein the compound of Formula I or Formula III is selected from the preferred compounds, and especially from the compounds selected from:
3-(2-Chloro-6-fluoro-benzylsulfanyl)-2-(2-chloro-6-fluoro-benzylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(5-methoxy-benzothiazol-2-ylsulfanyl)-2-(5-methoxy-benzothiazo-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
2-(Benzothiazole-2-sulfinylmethyl)-3-(benzothiazol-2-ylsulfanyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(6-nitro-benzothiazol-2-ylsulfanyl)-2-(6-nitro-benzothiazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-[4-(2-methoxycarbonyl-vinyl)-phenylsulfanyl]-2-[4-(2-methoxycarbonyl-vinyl)-phenylsulfanylmethyl]-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-(2,2-Dimethyl-propionyloxy)-3-(furan-2-ylmethylsulfanyl)-2-(furan-2-ylmethylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(4-methoxy-benzylsulfanyl)-2-(4-methoxy-benzylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
2-(1H-Benzoimidazol-2-ylsulfanylmethyl)-4-ethoxy-3-(1-ethyl-1H-benzoimidazol-2-ylsulfanyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzothiazol-2-ysulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(4-trifluoromethyl-pyrimidin-2-ylsulfanyl)-2-(4-trifluoromethyl-pyrimidin-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(4-methyl-pyrimidin-2-ysulfanyl)-2-(4-methyl-pyrimidin-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(pyrimidin-2-ylsulfanyl)-2-(pyrimidin-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester; and
3-(Benzoselenazol-2-ylsulfanyl)-2-(benzoselenazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
Certain embodiments of the invention provide novel and preferred combinations of substituent groups pendant from the formulae of the different inventions.
Excluded from the compositions of matter (but, e.g., not from the methods of use and pharmaceutical formulations) of the present invention is the compound 4-hydroxy-3-methanesulfonyl-2-methanesulfonylmethyl-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
Definitions
As used in the present specification, the following words and phrases are generally intended to have the meanings as set forth below, except to the extent that the context in which they are used indicates otherwise.
The term xe2x80x9coptionalxe2x80x9d or xe2x80x9coptionallyxe2x80x9d means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances in which it does not. For example, xe2x80x9coptionally substituted alkylxe2x80x9d means either xe2x80x9calkylxe2x80x9d or xe2x80x9csubstituted alkyl,xe2x80x9d as defined below. It will be understood by those skilled in the art with respect to any group containing one or more substituents that such groups are not intended to introduce any substitution or substitution patterns that are sterically impractical and/or synthetically non-feasible.
Certain compound, reactant, or reaction parameter abbreviations are defined as follows:
xe2x80x9cDCMxe2x80x9d refers to dichloromethane or methylene chloride
xe2x80x9cDMFxe2x80x9d refers to N,N-dimethyl formamide
xe2x80x9cEq.xe2x80x9d refers to equivalent.
xe2x80x9cMeOHxe2x80x9d refers to methanol.
xe2x80x9cTFAxe2x80x9d refers to trifluoroacetic acid.
The term xe2x80x9cacylxe2x80x9d refers to the groups xe2x80x94(O)xe2x80x94H, xe2x80x94C(O)-(optionally substituted alkyl), xe2x80x94C(O)-(optionally substituted cycloalkyl), xe2x80x94C(O)-(optionally substituted alkenyl), xe2x80x94C(O)-(optionally substituted cycloalkenyl), xe2x80x94C(O)-(optionally substituted aryl), xe2x80x94C(O)-(optionally substituted heteroaryl) and xe2x80x94C(O)-(optionally substituted heterocyclyl).
The term xe2x80x9cacyloxyxe2x80x9d refers to the moiety xe2x80x94O-acyl, including, for example, xe2x80x94Oxe2x80x94C(O)-alkylyl.
The term xe2x80x9calkoxyxe2x80x9d refers to the groups xe2x80x94O-alkyl, xe2x80x94O-alkenyl, xe2x80x94O-cycloalkyl, xe2x80x94O-cycloalkenyl, and xe2x80x94O-alkynyl. Preferred alkoxy groups are xe2x80x94O-alkyl and include, by way of example, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, and the like.
The term xe2x80x9csubstituted alkoxyxe2x80x9d refers to the groups xe2x80x94O-(substituted alkyl), xe2x80x94O-(substituted alkenyl), xe2x80x94O-(substituted cycloalkyl), xe2x80x94O-(substituted cycloalkenyl), xe2x80x94O-(substituted alkynyl) and xe2x80x94O-(optionally substituted alkylene)-alkoxy.
The term xe2x80x9calkylxe2x80x9d refers to a monoradical branched or unbranched saturated hydrocarbon chain preferably having from about 1 to 20 carbon atoms, more preferably about 1 to 10 carbon atoms, and even more preferably about 1 to 6 carbon atoms. This term is exemplified by groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, n-hexyl, n-decyl, tetradecyl, and the like.
The term xe2x80x9csubstituted alkylxe2x80x9d refers to an alkyl group in which 1 or more (up to about 5, preferably up to about 3) hydrogen atoms is replaced by a substituent independently selected from the group: xe2x95x90O, xe2x95x90S, acyl, acyloxy, optionally substituted alkoxy, optionally substituted amino, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally substituted amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, halogen, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl, and sulfonic acid. One of the preferred optional substituents for alkyl is hydroxy, exemplified by hydroxyalkyl groups, such as 2-hydroxyethyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl, and the like; dihydroxyalkyl groups (glycols), such as 2,3-dihydroxypropyl, 3,4-dihydroxybutyl, 2,4-dihydroxybutyl, and the like; and those compounds known as polyethylene glycols, polypropylene glycols and polybutylene glycols, and the like.
The term xe2x80x9calkylenexe2x80x9d refers to a diradical derived from the above-defined monoradical, alkyl. This term is exemplified by groups such as methylene (xe2x80x94CH2xe2x80x94), ethylene (xe2x80x94CH2CH2xe2x80x94), the propylene isomers [e.g., xe2x80x94CH2CH2CH2xe2x80x94 and xe2x80x94CH(CH3)CH2] and the like.
The term xe2x80x9csubstituted alkylenexe2x80x9d refers to a diradical derived from the above-defined monoradical, substituted alkyl. Examples of substituted alkylenes are chloromethylene (xe2x80x94CH(Cl)xe2x80x94), aminoethylene (xe2x80x94CH(NH2)CH2xe2x80x94), methylaminoethylene (xe2x80x94CH(NHMe)CH2xe2x80x94), 2-carboxypropylene isomers (xe2x80x94CH2CH(CO2H)CH2xe2x80x94), ethoxyethylene (xe2x80x94CH2CH2Oxe2x80x94CH2CH2xe2x80x94), ethyl(N-methyl)aminoethylene (xe2x80x94CH2CH2N(CH3)CH2CH2xe2x80x94), 1-ethoxy-2-(2-ethoxy-ethoxy)ethylene (xe2x80x94CH2CH2Oxe2x80x94CH2CH2xe2x80x94OCH2CH2xe2x80x94OCH2CH2xe2x80x94), and the like.
The term xe2x80x9caminoxe2x80x9d refers to the group xe2x80x94NH2.
The term xe2x80x9csubstituted aminoxe2x80x9d refers to the group xe2x80x94NHR or xe2x80x94NRR where each R is independently selected from the group: optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted cycloalkenyl, optionally substituted alkynyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, acyl, optionally substituted alkoxy, carboxy and alkoxycarbonyl.
The term xe2x80x9camino acidxe2x80x9d or xe2x80x9cnatural amino acidxe2x80x9d refers to any of the twenty (20) common amino acids as generally accepted in the peptide art and represent L-amino acids unless otherwise designated (with the exception of achiral amino acids such as glycine).
The term xe2x80x9csubstituted amino acidxe2x80x9d refers to an amino acid containing one or more additional chemical moieties that are not normally a part of the amino acid. Such substitutions can be introduced by a targeted deriviatizing agent that is capable of reacting with selected side chains or terminal residues and via other art-accepted methods. For example, cysteinyl residues most commonly are reacted with .alpha.-haloacetates (and corresponding amines), such as chloroacetic acid or chloroacetamide, to give carboxymethyl or carboxyamidomethyl derivatives. Cysteinyl residues also are derivatized by reaction with bromotrifluoroacetone, xcex1-bromo-xcex2-(5-imidozoyl)propionic acid, chloroacetyl phosphate, N-alkylmaleimides, 3-nitro-2-pyridyl disulfide, methyl 2-pyridyl disulfide, p-chloromercuribenzoate, 2-chloromercuri-4-nitrophenol, or chloro-7-nitrobenzo-2-oxa-1,3-diazole. Carboxyl side groups (aspartyl or glutamyl) are selectively modified by reaction with carbodiimides (Rxe2x80x2xe2x80x94Nxe2x80x94Cxe2x80x94Nxe2x80x94Rxe2x80x2) such as 1-cyclohexyl-3-(2-morpholinyl-(4-ethyl)carbodiimide or 1-ethyl-3 (4 azonia 4,4-dimethylpentyl)carbodiimide. Furthermore, aspartyl and glutamyl residues are converted to asparaginyl and glutaminyl residues by reaction with ammonium ions. Glutaminyl and asparaginyl residues are frequently deamidated to the corresponding glutamyl and aspartyl residues. Alternatively, these residues are deamidated under mildly acidic conditions. Other modifications include hydroxylation of proline and lysine, phosphorylation of hydroxyl groups of seryl or theonyl residues, methylation of the .alpha.-amino groups of lysine, arginine, and histidine side chains (see, e.g., T. E. Creighton, Proteins: Structure and Molecule Properties, W. H. Freeman and Co., San Francisco, pp. 79-86 (1983)), acetylation of the N-terminal amine, and, in some instances, amidation of the C-terminal carboxyl groups.
The term xe2x80x9caromaticxe2x80x9d refers to a cyclic or polycyclic moiety having a conjugated unsaturated (4n+2)xcfx80 electron system (where n is a positive integer), sometimes referred to as a delocalized xcfx80 electron system.
The term xe2x80x9carylxe2x80x9d refers to an aromatic cyclic hydrocarbon group of from 6 to 20 carbon atoms having a single ring (e.g., phenyl) or multiple condensed (fused) rings (e.g., naphthyl or anthryl). Preferred aryls include phenyl, naphthyl and the like.
The term xe2x80x9csubstituted arylxe2x80x9d refers to an aryl group as defined above, which unless otherwise constrained by the definition for the aryl substituent, is substituted with from 1 to 5 substituents, and preferably 1 to 3 substituents, independently selected from the group consisting of: xe2x95x90O, xe2x95x90S, acyl, acyloxy, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted alkyl (such as tri-halomethyl), optionally substituted alkynyl, optionally substituted amino, optionally substituted aryl, optionally substituted aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally substituted amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, halogen, optionally substituted heteroaryl, optionally substituted heteroaryloxy, optionally substituted heterocyclyl, optionally substituted heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl, and sulfonic acid. Preferred aryl substituents include alkyl, alkenyl, alkoxy, halo, cyano, nitro, trihalomethyl, carboxyalkenyl, and sulfinyl.
The term xe2x80x9caryloxyxe2x80x9d refers to the group xe2x80x94O-aryl.
The term xe2x80x9csubstituted aryloxyxe2x80x9d refers to the group xe2x80x94O-(substituted aryl).
The term xe2x80x9caralkylxe2x80x9d refers to the moiety xe2x80x9c-alkylene-arylxe2x80x9d each having the meaning as defined herein. Such aralkyl groups are exemplified by benzyl, phenethyl, 3-naphthylpropyl and the like.
The term xe2x80x9csubstituted aralkylxe2x80x9d refers to the moiety xe2x80x9c-(optionally substituted aklylene)-(optionally substituted aryl)xe2x80x9d, each having the meaning as defined herein, where at least one of the aryl or alkylene groups is substituted, e.g., 4-(N-methyl-pyrrolyl)pentylene.
The term xe2x80x9ccarbonylxe2x80x9d refers to the di-radical xe2x80x9cxe2x80x94C(xe2x95x90O)xe2x80x94xe2x80x9d, which is also illustrated as xe2x80x9cxe2x80x94C(O)xe2x80x94xe2x80x9d.
The term xe2x80x9c(optionally substituted alkoxy)carbonylxe2x80x9d refers to the groups: xe2x80x94C(O)O-(optionally substituted alkyl), xe2x80x94C(O)O-(optionally substituted cycloalkyl), xe2x80x94C(O)O-(optionally substituted alkenyl), and xe2x80x94C(O)O-(optionally substituted alkynyl). These moieties are also referred to as esters.
The term xe2x80x9c(optionally substituted amino)carbonylxe2x80x9d refers to the group xe2x80x94C(O)-(optionally substituted amino). This moiety is also referred to as a primary, secondary or tertiary carboxamide.
The term xe2x80x9c(optionally substituted amino)carbonyloxyxe2x80x9d refers to the group xe2x80x94Oxe2x80x94C(O)-(optionally substituted amino).
The term xe2x80x9ccarboxyxe2x80x9d or xe2x80x9ccarboxylxe2x80x9d refers to the moiety xe2x80x9cxe2x80x94C(O)OHxe2x80x9d, which is also illustrated as xe2x80x9cxe2x80x94COOHxe2x80x9d.
The term xe2x80x9ccognitive disordersxe2x80x9d refers to disorders generally characterized by symptoms of forgetfulness, confusion, memory loss, impairment in attention and memory, behavioral and relation disorders, abulia, lack of interest, affective disturbances, and/or, in some cases poor personal care. These symptoms may arise as a result of the general aging process and/or from organic brain disease, cerebrovascular disease, head injury, or developmental or genetic defects. Cognitive disorders include Alzheimer""s disease, senile dementia, anxiety, HIV-related dementia, diabetic neuropathies; depression; Parkinson""s disease; drug dependency; substance abuse; consciousness disorders, sleeping disorders, disorders of the circadian rhythm, mood disorders, epilepsy; Down""s syndrome; Huntington""s chorea or disease; stress-related somatic disorders; Pick""s disease, Friedreich""s ataxia, Creutzfeldt-Jacob disease; disorders associated with panic, phobia or stress.
The term xe2x80x9ccompound of Formula I or Formula IIIxe2x80x9d is intended to encompass the furanone derivatives of the invention as disclosed, and/or the pharmaceutically acceptable salts of such compounds or metal complexes thereof. In addition, the compounds of this invention include the keto and enol tautomers, individual stereochemical isomers (arising from the selection of substituent groups) and mixtures of tautomers and/or isomers.
The term xe2x80x9ccycloalkylxe2x80x9d refers to non-aromatic cyclic hydrocarbon groups of having about 3 to 40 (preferably about 4 to 15) carbon atoms having a single ring or multiple condensed rings. Such cycloalkyl groups include, by way of example, single ring structures such as cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, and the like, or multiple ring structures such as adamantanyl, and the like.
The term xe2x80x9csubstituted cycloalkylxe2x80x9d refers to a cycloalkyl group substituted with from 1 to 5 substituents, and preferably 1 to 3 substituents, independently selected from the group consisting of: xe2x95x90O, xe2x95x90S, acyl, acyloxy, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted alkyl (such as tri-halomethyl), optionally substituted alkynyl, optionally substituted amino, optionally substituted aryl, optionally substituted aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally substituted amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, halogen, optionally substituted heteroaryl, optionally substituted heteroaryloxy, optionally substituted heterocyclyl, optionally substituted heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl, and sulfonic acid. A cycloalkyl ring substituted with an alkyl group is also referred as xe2x80x9calkylcycloalkylxe2x80x9d.
The term xe2x80x9chaloxe2x80x9d or xe2x80x9chalogenxe2x80x9d refers to fluoro, chloro, bromo and iodo.
The term xe2x80x9cheteroarylxe2x80x9d refers to an aromatic cyclic hydrocarbon group having about 1 to 40 (preferably from about 3 to 15) carbon atoms and about 1 to 10 hetero atoms (preferably about 1 to 4 heteroatoms, selected from nitrogen, sulfur, selenium, phosphorus, and/or oxygen) within at least one ring. Such heteroaryl groups can have a single ring (e.g., pyridyl or furyl) or multiple condensed rings (e.g., indolizinyl or benzothienyl). Preferred heteroaryls include pyridyl, pyrrolyl and furyl. Other preferred heteroaryls include imidazole, triazole, tetrazole, thiadiazole, oxodiazole, pyrazole, benzoimidazole, benzooxazole, benzoselenazole, and benzothiazole.
The term xe2x80x9csubstituted heteroarylxe2x80x9d refers to a heteroaryl group as defined above, which unless otherwise constrained by the definition for the heteroaryl substituent, is substituted with from 1 to 5 substituents, and preferably 1 to 3 substituents, independently selected from the group consisting of: xe2x95x90O, xe2x95x90S, acyl, acyloxy, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted alkyl (such as tri-halomethyl), optionally substituted alkynyl, optionally substituted amino, optionally substituted aryl, optionally substituted aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally substituted amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, halogen, optionally substituted heteroaryl, optionally substituted heteroaryloxy, optionally substituted heterocyclyl, optionally substituted heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl, and sulfonic acid.
The term xe2x80x9cheteroaralkylxe2x80x9d refers to the moiety xe2x80x9c-alkylene-heteroarylxe2x80x9d each having the meaning as defined herein.
The term xe2x80x9csubstituted heteroaralkylxe2x80x9d refers to the moiety xe2x80x9c-(optionally substituted aklylene)-(optionally substituted heteroaryl)xe2x80x9d, each having the meaning as defined herein.
The term xe2x80x9cheteroaryloxyxe2x80x9d refers to the group xe2x80x94O-heteroaryl.
The terms xe2x80x9cheterocyclexe2x80x9d, xe2x80x9cheterocyclicxe2x80x9d and xe2x80x9cheterocyclylxe2x80x9d refer to a monoradical, saturated or unsaturated, non-aromatic cyclic hydrocarbon group having about 1 to 40 (preferably from about 3 to 15) carbon atoms and about 1 to 10 hetero atoms (preferably about 1 to 4 heteroatoms, selected from nitrogen, sulfur, phosphorus, and/or oxygen) within the ring. Such heterocyclic groups can have a single ring or multiple condensed rings. Preferred heterocyclics include morpholino, piperidinyl, and the like.
The terms xe2x80x9csubstituted heterocyclexe2x80x9d, xe2x80x9csubstituted heterocyclicxe2x80x9d and xe2x80x9csubstituted heterocyclylxe2x80x9d refer to a heterocyclyl group as defined above, which unless otherwise constrained by the definition for the heterocycle, is substituted with from 1 to 5 substituents, and preferably 1 to 3 substituents, independently selected from the group consisting of: xe2x95x90O, xe2x95x90S, acyl, acyloxy, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted alkyl (such as tri-halomethyl), optionally substituted alkynyl, optionally substituted amino, optionally substituted aryl, optionally substituted aryloxy, azido, carboxyl, (optionally substituted alkoxy)carbonyl, (optionally substituted amino)carbonyl, cyano, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, halogen, optionally substituted heteroaryl, optionally substituted heteroaryloxy, optionally substituted heterocyclyl, optionally substituted heterocyclooxy, hydroxyl, nitro, sulfanyl, sulfinyl, sulfanyl and sulfonic acid.
The term xe2x80x9cheterocycloalkylxe2x80x9d refers to the moiety xe2x80x9c-alkylene-heterocyclexe2x80x9d each having the meaning as defined herein.
The term xe2x80x9csubstituted heterocycloalkylxe2x80x9d refers to the moiety xe2x80x9c-(optionally substituted aklylene)-(optionally substituted heterocycle)xe2x80x9d, each having the meaning as defined herein.
The term xe2x80x9cheterocyclooxyxe2x80x9d refers to the group xe2x80x94O-heterocycle.
The term xe2x80x9cinflammationxe2x80x9d, xe2x80x9cinflammatory conditionsxe2x80x9d, or xe2x80x9cinflammation conditionsxe2x80x9d includes but is not limited to muscle fatigue, osteoarthritis, rheumatoid arthritits, inflammatory bowel syndrome or disorder, skin inflammation, such as atopic dermatitis, contact dermatitis, allergic dermatitis, xerosis, eczema, rosacea, seborrhea, psoriasis, atherosclerosis, thermal and radiation burns, acne, oily skin, wrinkles, excessive cellulite, excessive pore size, intrinsic skin aging, photo aging, photo damage, harmful UV damage, keratinization abnormalities, irritation including retinoid induced irritation, hirsutism, alopecia, dyspigmentation, inflammation due to wounds, scarring or stretch marks, loss of elasticity, skin atrophy and gingivitis.
The term xe2x80x9cischemiaxe2x80x9d refers to deficiency of blood to an organ or tissue due to functional constriction or actual obstruction of a blood vessel. Cerebral ischemia, also known as stroke, usually results from the interruption or reduction of blood and oxygen to the blood vessels of the brain; more rarely this may be the result of an hemorrhage. Signs of stroke include paralysis, slurred speech, general confusion, impairment of gait, cortical sensory loss over toes, foot and leg, and urinary incontinence, to name just a few. Many types of heart disease including cardiac arrhythmias or diseases due to cardiac structural abnormalities may produce cerebral emboli. Atrial fibrillation from any cause, including rheumatic valvular disease, may result in emboli being produced which can migrate into the arteries of the brain. Emboli formation and migration can occur as a result of arteriosclerotic cardiovascular disease and myocardial infarction. Emboli formation is also a definite risk for intracardiac surgery and prosthetic valve replacement. Heart bypass surgery and angioplasty can result in the formation of microemboli which can migrate into the arteries of the brain and cause a series of occlusions in a number of arteries, resulting in mental impairment. Cerebral embolism is also the principal complication in the transplant of artificial hearts. Furthermore, the overall risk of stroke after any type of general surgery is 0.2 to 1 percent. The vegetations of acute and subacute bacterial endocarditis can give rise to emboli which can occlude a major intracranial artery. Populations at risk of ischemia include but are not limited to patients scheduled for coronary arterial bypass graft surgery (CABG), patients at risk for postoperative complications, patients with subarachnoid hemorrhage (SAH), patients with a first or second ischemic stroke, patients with acute ischemic stroke, patients undergoing cardiopulmonary resuscitation (CPR), patients with temporary lobectomy, patients with dominant hemisphere resection, patients receiving prophylactic brain radiation, patients with closed head trauma with neurological loss, patients with microvascular multi-infarct dementia, patients with homozygous and heterozygous MELAS (Mitochondrial myopathy, encephalopathy, lactacidosis, stroke); patients with atherosclerotic or progressive supranuclear palsy disease, patients with symptomatic and asymptomatic Huntington""s disease, patients with neonatal asphyxia, patients with meningitis or encephalitis, patients with post herpetic neuropathy, patients with intermittent claudication, patients with spinal cord injury, patients with Huntington""s disease, Amyotrophic Lateral Sclerosis (ALS) or Friedreich""s ataxia, patients with diabetic neuropathy or patients with a disease associated with a hypercoagulable state secondary to systemic disease, carcinoma, vasoconstriction (including reversible cerebral vasoconstriction, e.g. migraine, trauma, idiopathy), or venous conditions (including dehydration, pulmonary embolism, pericranial infection, postpartum and postoperative states and system cancer).
The term xe2x80x9cneurodegenerative disordersxe2x80x9d refers to disorders characterized by a loss of neurons and may or may not include an inflammatory process. Neurodegenerative disorders include stroke, head trauma, cerebral hypoxia, spinal cord injury, senile dementia, Alzheimer""s disease, amyotrophic lateral sclerosis (ALS), cerebral amyloid angiopathy, HIV-related dementia, Parkinson""s disease, Huntington""s disease, prion diseases, myasthenia gravis, Down""s syndrome, Creutzfelt-Jakob disease, diabetic neuropathy, neuropathic pain, encephalitis, meningitis, and Duchenne""s muscular dystrophy.
The term xe2x80x9cneuroinflammationxe2x80x9d or xe2x80x9cneuroinflammatory diseases, disorders or conditionsxe2x80x9d refers to diseases, disorders or conditions characterized by large numbers of reactive microglia in postmortem brain samples, indicative of an active inflammatory process (McGeer E. G. and McGeer P. L., xe2x80x9cNeurodegeneration and the immune systemxe2x80x9d. Calne D. B., ed. Neurodegenerative Diseases, 1994:277-300). Neuroinflammation refers to inflammation which occurs in response to brain injury or autoimmune disorders, and has been shown to cause destruction of healthy neuronal and/or cerebral tissue. Neuroinflammation relates to mechanisms implicated in a broad range of acute and chronic neurodegenerative disorders, including stroke, head trauma, cerebral amyloid angiopathy, HIV-related dementia, Huntington""s disease, prion diseases, meningitis, myelin degradation, Down""s syndrome, post-ischemic brain injury, encephalopathy, Parkinson""s disease, senile dementia, Alzheimer""s disease, amyotrophic lateral sclerosis, multiple sclerosis and certain disorders involving the peripheral nervous system, such as myasthenia gravis and Duchenne""s muscular dystrophy.
As used herein, xe2x80x9cpharmaceutically acceptable carrierxe2x80x9d or xe2x80x9cpharmaceutically acceptable excipientxe2x80x9d includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active ingredient, its use in the therapeutic compositions is contemplated. Supplementary active ingredients can also be incorporated into the compositions.
The term xe2x80x9cpharmaceutically acceptable saltxe2x80x9d refers to salts which retain the biological effectiveness and properties of the compounds of this invention and which are not biologically or otherwise undesirable. In many cases, the compounds of this invention are capable of forming acid and/or base salts by virtue of the presence of amino and/or carboxyl groups or groups similar thereto. Pharmaceutically acceptable base addition salts can be prepared from inorganic and organic bases. Salts derived from inorganic bases, include by way of example only, sodium, potassium, lithium, ammonium, calcium and magnesium salts. Salts derived from organic bases include, but are not limited to, salts of primary, secondary and tertiary amines, such as alkyl amines, dialkyl amines, trialkyl amines, substituted alkyl amines, di(substituted alkyl)amines, tri(substituted alkyl)amines, alkenyl amines, dialkenyl amines, trialkenyl amines, substituted alkenyl amines, di(substituted alkenyl)amines, tri(substituted alkenyl)amines, cycloalkyl amines, di(cycloalkyl)amines, tri(cycloalkyl)amines, substituted cycloalkyl amines, disubstituted cycloalkyl amine, trisubstituted cycloalkyl amines, cycloalkenyl amines, di(cycloalkenyl)amines, tri(cycloalkenyl)amines, substituted cycloalkenyl amines, disubstituted cycloalkenyl amine, trisubstituted cycloalkenyl amines, aryl amines, diaryl amines, triaryl amines, heteroaryl amines, diheteroaryl amines, triheteroaryl amines, heterocyclic amines, diheterocyclic amines, triheterocyclic amines, mixed di- and tri-amines where at least two of the substituents on the amine are different and are selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, heteroaryl, heterocyclic, and the like. Also included are amines where the two or three substituents, together with the amino nitrogen, form a heterocyclic or heteroaryl group.
Specific examples of suitable amines include, by way of example only, isopropylamine, trimethyl amine, diethyl amine, tri(iso-propyl)amine, tri(n-propyl)amine, ethanolamine, 2-dimethylaminoethanol, tromethamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, N-alkylglucamines, theobromine, purines, piperazine, piperidine, morpholine, N-ethylpiperidine, and the like.
Pharmaceutically acceptable acid addition salts may be prepared from inorganic and organic acids. Salts derived from inorganic acids include hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like. Salts derived from organic acids include acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, malic acid, malonic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluene-sulfonic acid, salicylic acid, and the like.
The term xe2x80x9csulfanylxe2x80x9d refers to the groups: xe2x80x94S-(optionally substituted alkyl), xe2x80x94S-(optionally substituted aryl), xe2x80x94S-(optionally substituted heteroaryl), xe2x80x94S-(optionally substituted heterocyclyl). Preferred sulfanyl groups include, by way of example, methylsulfanyl (xe2x80x94SCH3), n-(iso-propylsulfanyl) (xe2x80x94SCH(CH3)2) and the like.
The term xe2x80x9csulfinylxe2x80x9d refers to the groups: xe2x80x94S(O)-(optionally substituted alkyl), xe2x80x94S(O)-optionally substituted aryl), xe2x80x94S(O)-(optionally substituted heteroaryl), xe2x80x94S(O)-(optionally substituted heterocyclyl).
The term xe2x80x9csulfonylxe2x80x9d refers to the groups: xe2x80x94S(O2)-(optionally substituted alkyl), xe2x80x94S(O2)-optionally substituted aryl), xe2x80x94S(O2)-(optionally substituted heteroaryl), xe2x80x94S(O2)-(optionally substituted heterocyclyl).
The term xe2x80x9csulfonic acidxe2x80x9d refers to the group: xe2x80x94S(O2)xe2x80x94OH.
The term xe2x80x9ctautomersxe2x80x9d refers to compounds whose structures differ markedly in arrangement of atoms, but which exist in easy and rapid equilibrium. The most common kind of tautomerism involves structures that differ in the point of attachment of hydrogen. As is well-known in the art, the 3-hydroxy-5H-furan-2-one group in compounds such as the compounds of this invention can be in tautomeric equilibrium with the dihydrofuran 2,3-dione group: 
For convenience, all the compounds of this invention are shown as having the 3-hydroxy-5H-furan-2-one form, but it is to be understood that compounds of both tautomeric forms are intended to be within the scope of the invention.
The term xe2x80x9ctherapeutically effective amountxe2x80x9d refers to that amount of a compound of Formula I that is sufficient to effect treatment, as defined below, when administered to a mammal in need of such treatment. The therapeutically effective amount will vary depending upon the subject and disease condition being treated, the weight and age of the subject, the severity of the disease condition, the particular compound of Formula I or Formula III chosen, the dosing regimen to be followed, timing of administration, the manner of administration and the like, all of which can readily be determined by one of ordinary skill in the art.
The term xe2x80x9ctreatmentxe2x80x9d or xe2x80x9ctreatingxe2x80x9d means any treatment of a disease or disorder in a mammal, including:
preventing or protecting against the disease or disorder, that is, causing the clinical symptoms not to develop;
inhibiting the disease or disorder, that is, arresting or suppressing the development of clinical symptoms; and/or
relieving the disease or disorder, that is, causing the regression of clinical symptoms.
It will be understood by those skilled in the art that in human medicine, it is not always possible to distinguish between xe2x80x9cpreventingxe2x80x9d and xe2x80x9csuppressingxe2x80x9d since the ultimate inductive event or events may be unknown, latent, or the patient is not ascertained until well after the occurrence of the event or events. Therefore, as used herein the term xe2x80x9cprophylaxisxe2x80x9d is intended as an element of xe2x80x9ctreatmentxe2x80x9d to encompass both xe2x80x9cpreventingxe2x80x9d and xe2x80x9csuppressingxe2x80x9d as defined herein. The term xe2x80x9cprotection,xe2x80x9d as used herein, is meant to include xe2x80x9cprophylaxis.xe2x80x9d
The term xe2x80x9ceffective amountxe2x80x9d means a dosage sufficient to provide treatment for the disorder or disease state being treated. This will vary depending on the patient, the disease and the treatment being effected.
Nomenclature
The compounds of the present invention are named and numbered as described below, for example, with reference to Formulae Ia, Ib, Ic, and Id. 
Formula Ia represents the compound according to Formula I where R1 is xe2x80x94C(O)ORxe2x80x2 and R1 is ethyl; R2 and R3 are each 1H-benzoimidazol-2-yl; R4 is hydrogen; X is sulfur and Y is sulfur. The compound is shown without specifying stereo configuration. The compound of Formula Ia can be named: 3-(5-chloro-1H-benzoimidazol-2-ylsulfanyl)-2-(5-chloro-1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester. 
Formula Ib represents the compound of Formula I where R1 is xe2x80x94C(O)ORxe2x80x2 and R1 is ethyl; R2 and R3 are each a 2-amino-4-[1-(carboxymethyl-carbamoyl)-ethylcarbamoyl]-butyric acid; R4 is hydrogen; X is sulfur and Y is sulfur. The compound is shown without specifying stereo configuration. The compound of Formula Ib can be named: 3-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethylsulfanyl]-2-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethylsulfanylmethyl]-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid. The analogous compound corresponding to Formula Ib where X and Y are each xe2x80x94S(O)2xe2x80x94 can be named: 3-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethanesulfonyl]-2-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethanesulfonylmethyl]-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid. 
Formula Ic represents the compound of Formula I where R1 is xe2x80x94C(O)ORxe2x80x2 and R1 is ethyl; R4 is hydrogen; X and Y are sulfur and Xxe2x80x94R2 taken together with Yxe2x80x94R3 form a hydroxymethyl substituted aliphatic ring. The compound of Formula Ic can be named: 3-hydroxy-6-hydroxymethyl-2-oxo-5,6-dihydro-2H-1-oxa-4,7-dithia-azulene-8a-carboxylic acid ethyl ester 
Formula Id represents the compound according to Formula I where R1 is xe2x80x94C(O)ORxe2x80x2 and R1 is ethyl; R2 is 1H-benzoimidazole, Y taken together with R3 is xe2x80x94P(O)(ORxe2x80x2)2 where R1 is methyl; R4 is hydrogen; and X is xe2x80x94S(O)xe2x80x94. The compound of Formula Id can be named: 2-(1H-benzoimidazole-2-sulfinylmethyl)-3-(dimethoxy-phosphoryl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
In general, the nomenclature used in this Application was generated using version 2.1 of the AUTONOM(trademark) naming package within the ChemOffice(copyright) version 6.0 suite of programs by CambridgeSoft Corp (Cambridge, Mass.).
The terms xe2x80x9csolventxe2x80x9d, xe2x80x9cinert organic solventxe2x80x9d or xe2x80x9cinert solventxe2x80x9d mean a solvent inert under the conditions of the reaction being described in conjunction therewith. Solvents employed in synthesis of the compounds of the invention include, for example, methanol, acetone, water, acetonitrile, 1,4-dioxane, dimethylformamide (xe2x80x9cDMFxe2x80x9d), benzene, toluene, tetrahydrofuran (xe2x80x9cTHFxe2x80x9d), chloroform, methylene chloride (or dichloromethane), diethyl ether, pyridine and the like, as well as mixtures thereof. Unless specified to the contrary, the solvents used in the reactions of the present invention are inert organic solvents.
The term xe2x80x9cq.s.xe2x80x9d means adding a quantity sufficient to achieve a stated function, e.g., to bring a solution to the desired volume (i.e., 100%).
Unless specified to the contrary, the reactions described herein take place at atmospheric pressure within a temperature range from 0xc2x0 C. to 110xc2x0 C. (preferably from 0xc2x0 C. to 25xc2x0 C.; most preferably at xe2x80x9croomxe2x80x9d or xe2x80x9cambientxe2x80x9d temperature, e.g., 20xc2x0 C.). Further, unless otherwise specified, the reaction times and conditions are intended to be approximate, e.g., taking place at about atmospheric pressure within a temperature range of about 0xc2x0 C. to about 110xc2x0 C. (preferably from about 0xc2x0 C. to about 25xc2x0 C.; most preferably at about xe2x80x9croomxe2x80x9d or xe2x80x9cambientxe2x80x9d temperature, e.g., approximately 20xc2x0 C.) over a period of about 1 to about 10 hours (preferably about 5 hours). Parameters given in the Examples are intended to be specific, not approximate.
Isolation and purification of the compounds and intermediates described herein can be effected, if desired, by any suitable separation or purification procedure such as, for example, filtration, extraction, crystallization, column chromatography, thin-layer chromatography or thick-layer chromatography, or a combination of these procedures. Specific illustrations of suitable separation and isolation procedures can be had by reference to the examples hereinbelow. However, asymmetric synthetic approaches and other equivalent separation or isolation procedures can, of course, also be used.
Reaction Scheme 1 illustrates the synthesis of the compounds of Formula I via an aldol addition between pyruvate derivatives, followed by an intramolecular cyclization reaction in the presence of a base.
Reaction Scheme 2 illustrates synthesis of the compounds of Formula I where Xxe2x80x94R2 taken together with Yxe2x80x94R3 form an optionally substituted aliphatic or aromatic ring (where X and Y are xe2x80x94Sxe2x80x94).
Reaction Scheme 3 illustrates synthesis of the compounds of Formula III via a base catalyzed condensation between a pyruvate derivative and a carbonyl component of another molecule.
The compound ethyl-3-bromopyruvate is commercially available, e.g., from Aldrich Chemical Company, Milwaukee, Wis. Other reactants, are likewise commercially available or may be readily prepared by those skilled in the art using commonly employed methodology.
The starting materials employed in Reaction Scheme 1, Formulae 101 and 102, are prepared as described in co-pending U.S. application Ser. Nos. 10/138,937 and 10/138,032, by contacting a halopyruvate (preferably ethyl-3-bromopyruvate) with a precursor of the formula R2xe2x80x94Xxe2x80x94H or R3xe2x80x94Yxe2x80x94H, where R2 and R3 have the meanings previously described, and where X and Y are xe2x80x94N(Rxe2x80x2)xe2x80x94 or xe2x80x94Sxe2x80x94. Such starting materials include:
an aryl, aralkyl, heteroaryl or heteroaralkyl compound,
a nucleoside, amino acid, di-, tri- or tetra-peptide,
an aryl-amine, -thiol, -sulfane, -sulfone,
an aralkyl-amine, -thiol, -sulfane, -sulfone,
a heteroaryl-amine, -thiol, -sulfane, -sulfone, or
a heteroaralkyl-amine, -thiol, -sulfane, -sulfone,
and are contacted in an appropriate solvent (such as methanol, acetone, water, acetonitrile, 1,4-dioxane or DMF), optionally in the presence of an organic base (such as a tertiary amine or imidazole). The reaction takes place at a temperature from 0xc2x0 C. to 110xc2x0 C. (preferably 0xc2x0 C. to 25xc2x0 C.) for 30 minutes to 15 hours (preferably 3-5 hours), followed by removal of the solvent(s), isolation and purification to give the corresponding product of Formulae 101 or 102. Additional isolation and purification steps well known to those skilled in the art may be performed, e.g., to provide single stereo isomers and/or tautomers. Where X taken together with R2 or Y taken together with R2 is xe2x80x94P(O)(ORxe2x80x2)2 a phosphite precursor (typically a trialkylphosphite) is contacted with the halopryuvate. 
As illustrated in Reaction Scheme 1, Step 1, an aldol addition between two tautomeric pyruvate derivatives of Formulae 101 and 102 (where Ra and Rb are lower alkyl, preferably ethyl) gives the corresponding cyclized furanone derivative of Formula I/103. In the synthesis of many of the compounds of Formula I, the groups Xxe2x80x94R2 and Yxe2x80x94R3 will be the same the pyruvate derivative(s) of Formulae 101 and 102, which will be employed as a single reactant (without regard to tautomeric form). Aldol addition between pyruvate derivatives of Formulae 101 and 102 where R2 and R3 contain chiral centers, produces diastereomers. When R2 and R3 are achiral, it produces a racemic mixture and the resulting compound has only one chiral center at the 5-position of the furanone.
In each instance, the product(s) of Reaction Scheme 1, Step 1 will fall within the scope of the compounds of the present invention according to Formula I, where R1 is xe2x80x94C(O)ORxe2x80x2 (Rxe2x80x2 being a lower alkyl group corresponding to Ra or Rb) and R4 is hydrogen. The compounds of Formula I where R1 is xe2x80x94C(O)ORxe2x80x2 (Rxe2x80x2 being other than lower alkyl), xe2x80x94C(O)NRxe2x80x2Rxe2x80x3 or xe2x80x94CH2ORxe2x80x2xe2x80x3, or where R4 is other than hydrogen, can be prepared as illustrated after Step 1 in Reaction Scheme 1, (for example, by conversion of R1 lower alkyl ester to another ester, amide, free acid, alcohol or like moiety) employing reactants and conditions well known to those skilled in organic synthesis.
Reaction Scheme 2
The compounds of Formula I where Xxe2x80x94R2 taken together with Yxe2x80x94R3 form an optionally substituted aliphatic or aromatic ring (where X and Y are the same, such as xe2x80x94Sxe2x80x94) are synthesized, for example, as illustrated below with regard to Reaction Scheme 2. 
As illustrated in Reaction Scheme 2, Step 1, an optionally substituted di-thiol of Formula 201 [where Rc is optionally one or more substituents selected from lower alkyl, hydroxy(lower alkyl), sulfonic acid(lower alkyl), xe2x80x94C(O)ORxe2x80x2, or represents an optionally substituted aliphatic or aromatic ring] and a halopyruvate of Formula 202 are reacted to give the corresponding di-thiol-bridged di-pyruvate compound of Formula 203.
As illustrated in Reaction Scheme 2, Step 2, a compound of Formula 203 is cyclized to the corresponding compound of Formula I/204 under aldol addition conditions similar to those employed in Step 1 of Reaction Scheme 1. 
As illustrated in Reaction Scheme 3, a base catalyzed condensation between the pyruvate of Formula 301 wherein Ra is a lower alkyl group, preferably ethyl, and the carbonyl component of Formula 302 wherein Ra, R5, R6 and R7 are as described herein, can give the corresponding cyclized furanone derivative of Formula III, wherein R8 is hydrogen. The compounds of Formula III where R8 is other than hydrogen, can be prepared by ways well known in the art, for example, compounds wherein R8 is alkyl carbonyl can be prepared by acetylation of the,alcohol group in the presence of a base.
Preferred Processes and Last Steps
The preferred process for generating compounds of Formula I or III is as exemplified for the syntheses of Examples 1-34. This process involves preparation of pyruvate derivatives and the subsequent aldol addition and cyclization between two pyruvate derivatives. The preparation of pyruvate precursors has already been exemplified in the previous Applications U.S. Ser. Nos. 10/138,937 and 10/138,032. In this invention, the preferred process for the preparation of compounds of Formula I is the aldol addition and the subsequent cyclization between the tautomers, namely the enol and keto forms, of pyruvate derivatives in the presence of a base.
Thus, in one preferred aspect, the pyruvate derivatives are treated with a base.
In another preferred aspect, the cyclized furanone diastereoisomers are separated using reverse phase chromatography method if the pyruvate precursors containing chiral center(s).
In yet another preferred aspect, the cyclized furanone racemic mixture is separated using chiral column chromatography method if the pyruvate precursors containing achiral centers.
In still another preferred aspect, the stereoisomers are converted into different pharmaceutically acceptable salts either from one salt to another or from a salt-free entity as exemplified in Examples.
A compound of Formula I or Formula III is contacted with a pharmaceutically acceptable acid to form the corresponding acid addition salt.
A pharmaceutically acceptable acid addition salt of Formula I or Formula III is contacted with a base to form the corresponding free base of Formula I or Formula III.
Preferred Compounds
The compounds of Formula I and of Formula III encompass the furanone derivatives of the invention as disclosed, and/or the pharmaceutically acceptable salts of such compounds. In addition, the compounds of this invention include the individual stereochemical isomers or tautomers and mixtures thereof, arising from the selection of substituent groups.
Preferred for the compounds, pharmaceutical formulations, methods of manufacture and use of the present invention are the following combinations and permutations of substituent groups of Formula I (sub-grouped, respectively, in increasing order of preference):
1. X is the same as Y:
a. Especially where X and Y are xe2x80x94Sxe2x80x94 or xe2x80x94S(O)xe2x80x94, preferably xe2x80x94Sxe2x80x94.
i. Preferably where R4 is hydrogen.
ii. Preferably where R1 is xe2x80x94C(O)ORxe2x80x2 and Rxe2x80x2 is hydrogen or lower alkyl.
iii. Preferably where R2 is the same as R3.
Particularly where R2 and R3 are selected from optionally substituted alkyl, optionally substituted heteroaryl, optionally substituted heteroaralkyl, an optionally substituted amino acid or an optionally substituted di-, tri- or tetra-peptide, and especially as further described as preferred below.
2. R1 is xe2x80x94C(O)ORxe2x80x2; xe2x80x94xe2x80x94CH2ORxe2x80x2xe2x80x3 or xe2x80x94C(O)NRxe2x80x2Rxe2x80x3 where Rxe2x80x2, Rxe2x80x3 and Rxe2x80x2xe2x80x3 are hydrogen or lower alkyl
a. Preferably R1 is is xe2x80x94C(O)ORxe2x80x2, where Rxe2x80x2 is hydrogen or lower alkyl
i. Especially where R4 is hydrogen.
ii. Especially where R2 is the same as R3 
1. Particularly where R2 and R3 are selected from optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, optionally substituted heteroaralkyl, an optionally substituted amino acid or an optionally substituted di-, tri- or tetra-peptide, and especially as further described as preferred below.
3. R4 is hydrogen.
4. R2 is the same as R3:
a. Especially where R2 and R3 are selected from optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, optionally substituted heteroaralkyl, an optionally substituted amino acid or an optionally substituted di-, tri- or tetra-peptide.
i. Preferably where R2 and R3 are optionally substituted heteroaryl, optionally substituted heteroaralkyl, optionally substituted aryl or optionally substituted aralkyl.
Particularly where optionally substituted heteroaryl or optionally substituted heteroaralkyl is selected from: optionally substituted 4-pyridinyl, optionally substsituted 2-pyridinyl, optionally substituted 1H-benzoimidazol-2-yl, optionally substituted-1H-benzothiazol-2-yl, optionally substituted benzooxazole-2-yl; optionally substituted benselenazol-2-yl; optionally substituted 1H-[1,2,4]triazol-3-yl, optionally substituted 2H-[1,2,4]triazol-3-yl, optionally substituted 4H-[1,2,4]triazol-3-yl, optionally substituted [1,3,4]oxadiazol-2-yl, optionally substituted [1,2,4]thiadiazol-5-yl, optionally substituted [1,3,5]thiadiazol-2-yl optionally substituted 4,5-dihydro-thiazol-2-yl, optionally substituted 1H-pyrazolo[3,4-d]pyrimidin-6-yl, optionally substituted 1H-imidazol-2-yl, optionally substituted quinolyn-4-yl, optionally substituted pyrimidin-4-yl, optionally substituted pyrimidin-2-yl, optionally substituted 2H-chromen-7-yl, optionally substituted furan-2-yl-lower alkyl, and optionally substituted 3,4-dihydro-quinazolin-2-yl, and wherein the substitutents are selected from (C1-C8)alkyl, (C1-C8)alkenyl, halogen, haloalkyl, acyl, sulfonic acid, sulfonyl, amino, mono- or di-substituted amino, aryl, carboxy, carboxyvinyl, ester, amide, hydroxy, and alkoxy.
a. More preferably where optionally substituted heteroaryl or heteroaralkyl is selected from optionally substituted benzyl; optionally substituted 1-H-benzoimidazol-2-yl; optionally substituted benzothiazol-2-yl; optionally substituted benzooxazol-2-yl; optionally substituted benzosenlenazol-2-yl; optionally substituted furan-2-yl-lower alkyl; optionally substituted thiazol-2-yl; optionally substituted 1H-imidazol-2-yl; optionally substituted pyridine-2-yl; optionally substituted pyrimidin-2-yl; optionally substituted quinolinin-4-yl; optionally substituted [1,3,4]oxadiaazol-2-yl; optionally substituted 2H-[1,2,4]-triazol-3-yl; and optionally substituted [1,3,4]thiadiazole-2-yl; and wherein the substituents are selected from (C1-C8)alkyl, (C1-C8)alkenyl, halogen, haloalkyl, acyl, sulfonic acid, sulfonyl, amino, mono- or di-substituted amino, aryl, carboxy, carboxyvinyl, ester, amide, hydroxy, and alkoxy.
b. Most preferably 1-H-benzoimidazol-2-yl; benzothiazol-2-yl; 5-methoxy-benzothiazol-2-yl; 6-nitro-benzothiazol-2-yl; benzooxazol-2-yl; 5-amino-[1,3,4]thiadiazol-2-yl; furan-2-ylmethyl; pyridin-4-yl; 5-phenyl-[1,3,4]oxadiazol-2-yl; pyrrolidine-1-carbothioyl; 4-(2-methoxycarbonyl-vinyl)-phenyl; 4-trifluoromethyl-pyrimidin-2-yl; 4-methyl-pyrimidin-2-yl; and pyrimidin-2-yl.
xe2x80x83Especially wherein R1 is xe2x80x94C(O)ORxe2x80x2, R1 is selected from hydrogen and (C1-C8)alkyl; and R4 is hydrogen.
xe2x80x83Especially wherein R1 is xe2x80x94CH2ORxe2x80x2xe2x80x3; Rxe2x80x2xe2x80x3 is selected from hydrogen and (C1-C8)alkyl; and R4 is hydrogen.
xe2x80x83Especially wherein R1 is xe2x80x94C(O)NRxe2x80x2Rxe2x80x3; Rxe2x80x2 and Rxe2x80x3 are selected from hydrogen, (C1-C8)alkyl and hydroxy(C1-C8)alkyl; and R4 is hydrogen.
ii. Preferably where R2 and R3 are optionally substituted di-, tri- or tetra-peptides. Particularly (4-amino-4-carboxyburyrylamino-2-(carboxymethyl-carbamoyl)-ethyl.
iii. Preferably where R2 and R3 are optionally substituted alkyl or optionally substituted cycloalkyl.
Particularly R2 and R3 are selected from (C3-C8)cycloalkyl, butyl, 2-acetylamino-2-methoxycarbonyl-ethyl, 3-(2-carboxy-pyrrolidin-1-yl)-2-methyl-3-oxo-propyl, 2-carboxy-2-isobutyrylamino-ethyl, 2-methoxycarbonyl-ethyl, 3-ethoxycarbonylmethyl; methoxycarbonylmethyl, carboxymethyl-carbamoyl-ethyl, dimethylthiocarbamoyl, isobutyl, 2-hydroxy-1-methyl-propyl, 2,3-dihydroxy-propyl, and allyl.
iv. Preferably where R2 and R3 are optionally substituted aryl or optionally substituted aralkyl,
1. Particularly where optionally substituted aryl or optionally substituted aralkyl are selected from optionally substituted phenyl, optionally substituted naphthyl or optionally substituted benzyl.
a. More preferably where optionally substituted aryl or optionally substituted aralkyl are selected from: 4-methoxy-benzyl; 2,4-dichloro-benzyl; 2-chloro-6-fluoro-benzyl; 4-fluoro-benzyl; benzyl; 2-chloro-phenyl; and 2-chloro-4-fluoro-phenyl.
5. Xxe2x80x94R2 taken together with Yxe2x80x94R3 forms an optionally substituted aliphatic or aromatic ring.
a. Especially an optionally substituted dithia-cyclohexene, optionally substituted dithia-cycloheptene, 7,8-dihydro-6H-5,9-dithia-benzocycloheptene,
i. Particularly 1,4-dichloro-7,8-dihydro-6H-5,9-dithia-benzocycloheptene, 2,3-dimethyl-[1,4]dithiepane, or [1,3]dithiane-2-thione.
6. Metal complex where the metal is selected from divalent copper, manganese and zinc
a. Especially where the metal is selected from Cu2+Cl2, Mn2+Cl2, and Zn2+Cl2,
i. Particularly with a compound of Formula I wherein XR2 and YR3 are both benzoimidazol-2-ylsulfanyl.
Of the compounds where Xxe2x80x94R2 and/or Yxe2x80x94R3 are represented by Formula II, preferred are those compounds the substituents of which are selected from the following groups:
R2.1 is xe2x80x94C(O)xe2x80x94Oxe2x80x94Rxe2x80x2 where Rxe2x80x2 is hydrogen or lower alkyl, especially ethyl;
R2.2 is hydrogen;
R2.3 is xe2x80x94CH2xe2x80x94Sxe2x80x94;
R2.4 is hydrogen, optionally substituted lower alkyl, optionally substituted aralkyl, optionally substituted heteroaralkyl;
R2.5 is hydrogen or lower alkyl, especially hydrogen; and/or
k, m and n are respectively: 0,2,1; 1,0,1; or 2,0,1.
Also preferred for the compounds, pharmaceutical formulations, methods of manufacture and use of the present invention are the following combinations and permutations of substituent groups of Formula III (sub-grouped, respectively, in increasing order of preference):
1. Yxe2x80x2 is xe2x80x94Sxe2x80x94, xe2x80x94S(O)xe2x80x94 or xe2x80x94S(O)2xe2x80x94; especially where Yxe2x80x2 is xe2x80x94Sxe2x80x94.
i. Preferably where R7 is selected from optionally substituted phenyl, optionally substituted naphthalenyl, optionally substituted benzyl, optionally substituted 1-H-benzoimidazol2-yl, optionally substituted benzothiazole-2yl, optionally substituted benzooxazole-2-yl, optionally substituted furan-2-yl-lower alkyl, optionally substituted thiazol-2-yl, optionally substituted 1H-imidazol-2-yl, optionally substituted pyridine-2-yl, optionally substituted pyrimidin-2-yl, optionally substituted quinolinin-4-yl; optionally substituted [1,3,4]oxadiaazol-2-yl, optionally substituted 2H-[1,2,4]-triazol-3-yl.
a. more preferably where R7 is selected from benzyl; 4-fluorobenzyl; 1-H-benzoimidazol-2-yl; 5-methyl-1-H-benzoimidazol2-yl; benzothiazole-2yl; 5-chloro-benzothiazole-2yl; and 4-phenyl-thiazol-2-yl.
ii. Preferably where R8 is hydrogen
iii. Preferably where R5 is xe2x80x94C(O)ORa or xe2x80x94C(O)Rc, Ra is selected from hydrogen, (C1-C8)alkyl, and (C1-C8)alkyl-(C3-C8)cycloalkyl, and Rc is selected from hydrogen, (C1-C8)alkyl, and aryl,
a. More preferably where R6 is hydrogen or xe2x80x94C(O)ORa and Ra is selected from hydrogen and (C1-C8)alkyl.
iv. Preferably where R5 is xe2x80x94C(O)Rc, and Rc is selected from hydrogen, (C1-C8)alkyl, and aryl, and R6 is hydrogen.
2. R5 is xe2x80x94C(O)ORa or xe2x80x94C(O)Rc, Ra is selected from hydrogen, (C1-C8)alkyl, and (C1-C8)alkyl-(C3-C8)cycloalkyl, and and Rc is selected from hydrogen, (C1-C8)alkyl, and aryl.
i. Especially where R8 is hydrogen.
ii. Especially where R7 is selected from optionally substituted phenyl, optionally substituted naphthalenyl, optionally substituted benzyl, optionally substituted 1-H-benzoimidazol2-yl, optionally substituted benzothiazole-2yl, optionally substituted benzooxazole-2-yl, optionally substituted furan-2-yl-lower alkyl, optionally substituted thiazol-2-yl, optionally substituted 1H-imidazol-2-yl, optionally substituted pyridine-2-yl, optionally substituted pyrimidin-2-yl, optionally substituted quinolinin-4-yl; optionally substituted [1,3,4]oxadiaazol-2-yl, optionally substituted 2H-[1,2,4]-triazol-3-yl.
a. Preferably where R7 is selected from benzyl; 4-fluorobenzyl; 1-H-benzoimidazol-2-yl; 5-methyl-1-H-benzoimidazol2-yl; benzothiazole-2yl; 5-chloro-benzothiazole-2yl; and 4-phenyl-thiazol-2-yl.
3. R5 and R6 taken together with the atom to which they are attached form a ring optionally incorporating one or more additional heteroatoms chosen from N, O or S and optionally substituted with one or more substitutents selected from the group consisting of optionally substituted lower alkyl, halo, carboxy, and oxo;
a. Especially a pyrimidine 2,4,6-trione ring or a cyclohexanone ring.
4. R5 and R7 together with the atoms to which they are attached form a ring optionally incorporating one or more additional heteroatoms chosen from N, O or S and optionally substituted with one or more substituents selected from the group consisting of optionally substituted lower alkyl, halo, carboxy and oxo;
a. Especially a 3-methyl-thiomorpholin-3-ol ring and the compound formed is 1,4-dihydro-4-methyl-3a,4-dihydro-3-oxa-10-thia-4a, 9-diaza-cyclopenta[b]fluoren-2-one.
The preferred compounds include the following, as well as their stereoisomer, tautomers, salts, and mixtures thereof:
4-(Benzothiazol-2-ylsulfanyl)-3-hydroxy-1-oxa-spiro[4.5]dec-3-ene-2,6-dione;
Methanesulfonic acid 3-(1H-benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-ylmethyl ester;
3-(Benzothiazol-2-ylsulfanyl)-4-hydroxy-5-oxo-5H-furan-2,2-dicarboxylic acid diethyl ester;
3-(5-Chloro-benzothiazol-2-ylsulfanyl)-4-hydroxy-5-oxo-5H-furan-2,2-dicarboxylic acid diethyl ester;
3-[9-(3,4-Dihydroxy-5-hydroxymethyl-tetrahydro-furan-2-yl)-2-methyl-9H-purin-6-ylsulfanyl]-2-[9-(3,4-dihydroxy-5-hydroxymethyl-tetrahydro-furan-2-yl)-2-methyl-9H-purin-6-ylsulfanylmethyl]-4 -hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(2-methyl-propane-1-sulfonyl)-2-(2-methyl-propane-1-sulfonylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(9H-purin-6-ylsulfanyl)-2-(9H-purin-6-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid methyl ester;
4-Hydroxy-5-oxo-3-(5-phenyl-2H-[1,2,4]triazol-3-ylsulfanyl)-2-(5-phenyl-2-[1,2,4]triazol-3-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-2-methyl-3-(5-methyl-1H-benzoimidazol-2-ylsulfanyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-(1H-Benzoimidazol-2-ylsulfanyl)-5-(1H-benzoimidazol-2-ylsulfanylmethyl)-3-hydroxy-5-(4-methyl-piperazine-1-carbonyl)-5H-furan-2-one;
4-Hydroxy-5-oxo-3-(3-sulfo-propylsulfanyl)-2-(3-sulfo-propylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(2-sulfo-ethylsulfanyl)-2-(2-sulfo-ethylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(2-Dimethylamino-ethylsulfanyl)-2-(2-dimethylamino-ethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester, as hydrochloric acid salt; and
3-[3-(2-Carboxy-pyrrolidin-1-yl)-2-methyl-3-oxo-propylsulfanyl]-2-[3-(2-carboxy-pyrodin-1-yl)-2-methyl-3-oxo-propylsulfanylmethyl]4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
The more preferred compounds include the following, as well as their stereoisomers, tautomers, salts, and mixtures thereof:
4-(1H-Benzoimidazol-2-ylsulfanyl)-3-hydroxy-5-thiazol-2-yl-5H-furan-2-one;
4-(1H-Benzoimidazol-2-ylsulfanyl)-3-hydroxy-1-oxa-7,9-diaza-spiro[4.5]dec-3-ene-2,6,8,10-tetraone;
Phosphoric acid mono-[3-(benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-ylmethyl]ester;
4-(Benzothiazol-2-ylsulfanyl)-3-hydroxy-1-oxa-7,9-diaza-spiro[4.5]dec-3-ene-2,6,8,10-tetraone;
2-(Furan-2-ylmethanesulfinylmethyl)-3-(furan-2-ylmethylsulfanyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(4-phenyl-thiazol-2-ylsulfanyl)-2,5-dihydro-furan-2-carboxylic acid;
3-[4-(2-Carboxy-vinyl)-phenylsulfanyl]-2-[4-(2-carboxy-vinyl)-phenylsulfanylmethyl]4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
Di-[2-(4-Hydroxy-5-oxo-2-carboxylic acid methyl ester)]-disulfide;
4-(5-sulfo-1H-benzoimidazol-2-ylsulfanyl)-5-(5-sulfo-1H-benzoimidazol-2-ylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
3-(1H-Benzoimidazol-2-ylsulfanyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(9H-purin-6-ylsulfanyl)-2-(9H-purin-6-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(5-methyl-1H-benzoimidazol-2-ylsulfanyl)-2-(5-methyl-1H-benzoimidazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Hexylsulfanyl-2-hexylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-(1H-Benzoimidazol-2-ylsulfanyl)-5-(1H-benzoimidazol-2-ylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
4-Hydroxy-3-(1H-imidazol-2-ylsulfanyl)-2-(1H-imidazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(7-trifluoromethyl-quinolin-4-ylsulfanyl)-2-(7-trifluoromethyl-quinolin-4-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(2-Diethylamino-ethylsulfanyl)-2-(2-diethylamino-ethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(5-sulfo-1H-benzoimidazol-2-ylsulfanyl)-2-(5-sulfo-1H-benzoimidazol-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(pyrrolidine-1-carbothioylsulfanyl)-2-(pyrrolidine-1-carbothioylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid methyl ester;
4-Hydroxy-3-(2-methoxycarbonyl-ethylsulfanyl)-2-(2-methoxycarbonyl-ethylsufanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-methoxycarbonylmethylsulfanyl-2-methoxycarbonylmethylsulfanylmethyl-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(5-methoxy-1H-benzoimidazol-2-ylsulfanyl)-2-(5-methoxy-1H-benzoimidazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(5-nitro-1H-benzoimidazol-2-ylsulfanyl)-2-(5-nitro-1H-benzoimidazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester; and
4-Hydroxy-5-oxo-3-p-tolysulfanyl-2-p-tolylsulfanylmethyl-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
The most preferred compounds include the following as well as their stereoisomers, tautomers, salts, and mixtures thereof:
4-(1H-Benzoimidazol-2-ylsulfanyl)-5-(1H-benzoimidazol-2-ylsulfanylmethyl)-3-hydroxy-5-thiazol-2-yl-5H-furan-2-one;
3-(Benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid (2-hydroxy-ethyl)-amide;
4-(Benzothiazol-2-ylsulfanyl)-5-benzoyl-3-hydroxy-5H-furan-2-one;
3-(Benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
Dimethylamino-acetic acid 3-(benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-ylmethyl ester;
4-(5-Chloro-benzothiazol-2-ylsulfanyl)-5-(5-chloro-benzothiazol-2-ylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
4-(Benzothiazol-2-ylsulfanyl)-5-(benzothiazol-2-ylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
3-(5,6-Dichloro-1H-benzoimidazol-2-ylsulfanyl)-2-(5,6-dichloro-1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(1H-Benzoimidazol-2-ylsulfanyl)-4-hydroxy-5-oxo-5H-furan-2,2-dicarboxylic acid diethyl ester;
4-(Furan-2-ylmethylsulfanyl)-5-(furan-2-ylmethylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
5-Acetyl4-(benzothiazol-2-ylsulfanyl)-3-hydroxy-5H-furan-2-one;
2-(Furan-2-ylmethanesulfinylmethyl)-3-(furan-2-ylmethanesulfonyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Furan-2-ylmethanesulfonyl)-2-(furan-2-ylmethanesulfonylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Benzylsulfanyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-methylsulfanyl-2-methylsulfanylmethyl-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(5-Amino-[1,3,4]thiadiazol-2-ylsulfanyl)-2-(5-amino-[1,3,4]thiadiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
3-(Benzothiazol-2-ylsulfanyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
3-Hydroxy-5,6-dimethyl-2-oxo-5,6-dihydro-2H-1-oxa-4,7-dithia-azulene-8a-carboxylic acid ethyl ester;
4-Hydroxy-3-(5-methyl-1H-benzoimidazol-2-ylsulfanyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid 2-isopropyl-5-methyl-cyclohexyl ester;
3-(2-Dimethylamino-ethylsulfanyl)-2-(2-dimethylamino-ethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
3-(Furan-2-ylmethylsulfanyl)-2-(furan-2-ylmethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(1-methyl-1H-imidazol-2-ylsulfanyl)-2-(1-methyl-1H-imidazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Cyclopentylsulfanyl-2-cyclopentylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-isobutylsulfanyl-2-isobutylsulfanylmethyl-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(naphthalen-2-ylsulfanyl)-2-(naphthalen-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(1-phenyl-1H-tetrazol-5-ylsulfanyl)-2-(1-phenyl-1H-tetrazol-5-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(thiazol-2-ylsulfanyl)-2-(thiazol-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(2-Chloro-phenylsulfanyl)-2-(2-chloro-phenylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzooxazol-2-ylsulfanyl)-2-(benzooxazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
4-Hydroxy-5-oxo-3-(pyridin-4-ylsulfanyl)-2-(pyridin-4-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
5,8-Dichloro-3-hydroxy-2-oxo-2H-1-oxa-4,9-dithia-benzo[f]azulene-10a-carboxylic acid ethyl ester;
3-(5-Chloro-benzothiazol-2-ylsulfanyl)-2-(5-chloro-benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(5-phenyl-[1,3,4]oxadiazol-2-ylsulfanyl)-2-(5-phenyl-[1,3,4]oxadiazol-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(5-Amino-2H-[1,2,4]triazol-3-ylsulfanyl)-2-(5-amino-2H-[1,2,4]triazol-3-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(3-Amino-[1,2,4]thiadiazol-5-ylsulfanyl)-2-(3-amino-[1,2,4]thiadiazol-5-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-[2-(4-Amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethanesulfonyl]-2-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethanesulfonylmethyl]-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
R-3-[2-(4-Amino4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethylsulfanyl]-2-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)ethylsulfanylmethyl]4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
S-3-[2-(4-Amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethylsulfanyl]-2-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)ethylsulfanylmethyl]4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
R-3-[2-(4-Amino4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)-ethylsulfanyl]-2-[2-(4-amino-4-carboxy-butyrylamino)-2-(carboxymethyl-carbamoyl)ethylsulfanylmethyl]4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid;
3-(2-Acetylamino-2-methoxycarbonyl-ethylsulfanyl)-2-(2-acetylamino-2-methoxycarbonyl-ethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
(S)-3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester; and
(R)-(3-(1H-Benzoimidazol-2-ylsulfanyl)-2-(1H-benzoimidazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
Other most preferred compounds include the following as well as their stereoisomers, tautomers, salts, and mixtures thereof:
3-(2-Chloro-4-fluoro-phenylsulfanyl)-2-(2-chloro-4-fluoro-phenylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(4-Fluoro-benzylsulfanyl)-4-hydroxy-5-oxo-5H-furan-2,2-dicarboxylic acid diethyl ester;
4-(Benzooxazol-2-ylsulfanyl)-5-(benzooxazol-2-ylsulfanylmethyl)-3-hydroxy-5-hydroxymethyl-5H-furan-2-one;
3-(2-Chloro-6-fluoro-benzylsulfanyl)-2-(2-chloro-6-fluoro-benzylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(5-methoxy-benzothiazol-2-ylsulfanyl)-2-(5-methoxy-benzothiazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(2,4-Dichloro-benzylsulfanyl)-2-(2,4-dichloro-benzylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
2-(Benzothiazole-2-sulfinylmethyl)-3-(benzothiazol-2-ylsulfanyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(6-nitro-benzothiazol-2-ylsulfanyl)-2-(6-nitro-benzothiazol-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Furan-2-ylmethanesulfinyl)-2-(furan-2-ylmethanesulfinylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzooxazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid methyl ester;
4-Hydroxy-3-[4-(2-methoxycarbonyl-vinyl)-phenylsulfanyl]-2-[4-(2-methoxycarbonyl-vinyl)-phenylsulfanylmethyl]-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Furan-2-ylmethylsulfanyl)-2-(furan-2-ylmethylsulfanylmethyl)-4-isobutyryloxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-(2,2-Dimethyl-propionyloxy)-3-(furan-2-ylmethylsulfanyl)-2-(furan-2-ylmethylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-(2,2-Dimethyl-propionyloxy)-3-ethoxycarbonylmethylsulfanyl-2-ethoxycarbonylmethylsulfanylmethyl-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(4-phenyl-thiazol-2-ylsulfanyl)-2-(4-phenyl-thiazol-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Furan-2-ylmethylsulfanyl)-2-(furan-2-ylmethylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Butylsulfanyl-2-butylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(4-methoxy-benzylsulfanyl)-2-(4-methoxy-benzylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-Benzylsulfanyl-2-benzylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(4-methoxy-phenylsulfanyl)-2-(4-methoxy-phenylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
2-(1H-Benzoimidazol-2-ylsulfanylmethyl)-4-ethoxy-3-(1-ethyl-1H-benzoimidazol-2-ylsulfanyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzothiazol-2-ylsulfanyl)-2-(benzothiazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(1-oxy-pyridin-2-ylsulfanyl)-2-(1-oxy-pyridin-2-ylsulfanylmethyl)-2,5-dihydrofuran-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(4-trifluoromethyl-pyrimidin-2-ylsulfanyl)-2-(4-trifluoromethyl-pyrimidin-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-3-(4-methyl-pyrimidin-2-ylsulfanyl)-2-(4-methyl-pyrimidin-2-ylsulfanylmethyl)-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
4-Hydroxy-5-oxo-3-(pyrimidin-2-ylsulfanyl)-2-(pyrimidin-2-ylsulfanylmethyl)-2,5-dihydro-furan-2-carboxylic acid ethyl ester;
3-(Benzoselenazol-2-ylsulfanyl)-2-(benzoselenazol-2-ylsulfanylmethyl)-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester; and
3-Cyclohexylsulfanyl-2-cyclohexylsulfanylmethyl-4-hydroxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid ethyl ester.
General Utility
Compounds of the present invention are useful in treating a number of disorders, particularly those characterized by oxidative stress and/or inflammation. In particular, compounds of the present invention can be used in the treatment of cerebral ischemia (xe2x80x9cstrokexe2x80x9d most often caused by thrombosis, vasoconstriction and embolism), myocardial ischemia (including chronic stable angina, angina pectoris, unstable angina and Prinzmetal""s angina, silent ischemia, reinfarction, reocclusion, restenosis, myocardial infarction and other forms of heart disease), diabetes, renal disease, pre-menstrual syndrome, asthma, cardiopulmonary inflammatory disorders, chronic heart failure, rheumatoid arthritis, muscle fatigue, irritable bowel syndrome, inflammatory bowel disease, intermittent claudication and for the preservation of allograft tissue for transplantation. Compounds of the present invention are also useful in treating conditions falling with the group of dermatologic conditions, in particular prevention and protecting skin tissue against age-related damage or damage resulting from insults such as harmful ultraviolet (UV) radiation, stress and fatigue, and in the treatment of contact dermatitis, skin irritation, skin pigmentation, psoriasis, or acne. Compounds of the present invention are also useful in treating a number of disorders associated with neuroinflammation, cognition, and neurodegeneration, particularly Friedreich""s ataxia, epilepsy, Parkinson""s disease, Alzheimer""s disease, and senile dementia.
Without subscribing to a particular theory or mechanism of action, compounds of the invention may target certain enzymes known as xe2x80x9coxidoreductasesxe2x80x9d that function widely across a variety of physiological processes. In particular, oxidoreductases catalyze reactions in which two molecules interact so that one molecule is oxidized and the other is reduced, with a molecule of water entering the reaction. Some of the most important oxidoreductases include, for example, lyases, lactases, dehydrogenases (including ubiquinone), reductases, peroxidases, nitric acid synthases, cholesterol oxidases, acyl-coenzyme A dehydrogenases and reductases, hydroxylases, and the like. These enzymes play roles in such essential processes as digestion, signal transduction, maintenance of ionic homeostasis, and the like. Alterations in oxidoreductases are thought to account for as many as 3% of all known human genetic diseases. In addition to the diseases and disorders listed above, abnormalities in oxidoreductase activity may underly such disorders as congestive heart failure, respiratory chain defects (e.g., abnormalities associated with enzymes of the respiratory chain), glycogen storage disease, rheumatoid arthritis, amyotrophic lateral sclerosis (ALS), chronic alcohol liver damage (CALD), Refsum""s disease (hereditary neuropathy), Crohn""s disease, Eales Disease (pervasculitis), prion diseases, Huntington""s Disease, cataracts, multiple sclerosis, acute respiratory distress syndrome (ARDS), Zellweger Syndrome (peroxisomal biogenesis), polycystic ovary syndrome, Alpers Syndrome (encephalopathy), steatosis/steatohepatitis, metabolic syndrome, diabetes, asthma, Fanconi anemia, retinopathy, age-related macular degeneration (AMD), pre-eclampsia, cholestatic liver disease, end-stage renal disease; Creutzfeldt-Jakob Disease (CJD), and sickle cell disease.
Testing
This section describes how compositions incorporating compositions of the present invention are selected, using in vitro and/or in vivo animal models, for example, and used as therapeutic interventions in the exemplary indications, i.e., stroke, chronic heart failure, myocardial infarction, and Alzheimer""s disease.
Insults to the brain that disrupt its blood supply, as in ischemia, or its oxygen supply, as in hypoxia (low oxygen) or anoxia (no oxygen), rapidly cause neuronal imbalance leading to cell death (Flynn, C. J., et al., 1989, in G. Siegel et al., (Eds), Basic Neurochemistry, Raven Press, NY). Investigations into the cellular and molecular mechanisms that lead to neuronal damage and inflammation associated with various types of brain ischemia can be carried out using in vitro model systems, such as primary cell cultures, that retain the metabolic characteristics of neurons in vivo. The use of such cell-based models has led to advances in identification of biochemical mechanisms leading to neuronal death in conditions such as anoxia, hypoglycemia, excitotoxicity, and exposure to reactive oxygen species. Neuronal cell lines such as the pheochromocytoma cell line, PC12, are also useful models for studying the effects of oxidative stress on the structure and function of neuron-specific proteins that are expressed in the cell lines. As many neuronal cell lines do not express all the properties of genuine neurons, primary neuronal cultures are now widely used as in vitro models in which to discern the processes that occur in intact brain.
In vitro models of ischemia approximate oxygen and glucose deprivation that mimic in vivo conditions, for example, by placing neuronal cultures into large anaerobic or hypoxic chambers and exchanging culture medium with de-oxygenated and defined ionic composition media. The toxic overstimulation of neuronal glutamate receptors, especially N-methyl-D-aspartate (NMDA) receptors, contributes to hypoxic-ischemic neuronal injury (Choi, D. M., 1988, Neuron 1: 623-634), ischemic induction of reactive oxygen species (ROS) (Watson, B. D., et al., 1988, Ann NY Acad Sci., 59: 269-281), excessive calcium influx (Grotta, J. C., 1988, Stroke 19: 447-454), arachidonic acid increase (Siesjo, B. K., 1981, J. Cereb. Blood Flow Metab. 1: 155-186) and DNA damage (MacManus, J. P., et al., 1993, Neurosci. Lett., 164: 89-92), each causing a cascade of neurodegeneration.
Primary embryonic hippocampal neuronal cells are widely recognized as useful in models of neuronal function. The hippocampus is a source of a relatively homogenous population of neurons with well-characterized properties typical of central nervous system (CNS) neurons in general. Pyramidal neurons, the principal cell type in the hippocampus, have been estimated to account for 85% to 90% of the total neuronal population (Banker and Goslin, 1998, Culturing Nerve Cells, 2nd edition. The MIT Press, Cambridge, Mass.). The hippocampus also exhibits a remarkable capacity for activity-dependent changes in synaptic function, such as long-term potentiation (Hawkins R D, Kandel E R, Siegelbaum S A. (1993) Learning to modulate transmitter release: themes and variations in synaptic plasticity [review], Ann. Rev Neurosci. 16:625-665.).
In experiments carried out in support of the present invention according to methods detailed in the Examples, anoxia/ischemia was induced in primary cultures of hippocampal neuronal cells, and compounds were tested for their ability to prevent cell death. Certain compounds found to have activity in such in vitro assays are then further tested in one or more animal models of cerebral ischemia (xe2x80x9cstrokexe2x80x9d), such as the middle cerebral artery occlusion (MCAO) model in rats.
Briefly, primary cultures of hippocampal neurons are used to test compounds for activity in neuronal protection. Hippocampal cultures are typically prepared from 18- to 19-day fetal rats. At this age, the generation of pyramidal neurons, which begins in the rat at about E15, is essentially complete. The brain tissue at this stage is relatively easy to dissociate, the meninges are removed readily, and the number of glial cells still is relatively modest (Park L C, Calingasan N Y, Uchida K, Zhang H, Gibson G E. (2000). Metabolic impairment elicits brain cell type-selective changes in oxidative stress and cell death in culture. J Neurochem 74(1):114-124).
In order to evaluate the activity of compounds of the present invention, a test compound is assessed for its ability to protect cells against one or more standard stressors, including hypoxia, as detailed in the Examples. In general, desirable therapeutic compound candidates are effective in this model at concentrations less than about 1 mM and even more preferably, less than about 100 xcexcM. By effective, it is meant that such compounds protect at least 20%, preferably 30%, more preferably 40% and even more preferably 50% or more of the cells tested from stressor-induced death. By way of example, compounds that are effective in providing protection over a concentration a range of about 1 to 1000 xcexcM would be expected to provide neuroprotection in vivo. Since precise values may vary depending upon the specific conditions under which the neuroprotective cell assay is carried out, it is the intent of the present disclosure to provide the foregoing criteria as guidance in the form of a benchmark against which to compare subsequently tested compounds, rather than to provide absolute concentrations at which the compounds of the present invention are considered to be effective. Typically, compounds that are found to be neuroprotective in such in vitro cell systems are then further tested in an in vivo animal model of neuroprotection, such as the rat middle cerebral artery occlusion model described below, or other appropriate models such as are well known in the art.
Cerebral ischemic insults are modeled in animals by occluding vessels to, or within, the cranium (Molinari, G. F., 1986, in H. J. M. Barnett, et al., (Eds) Stroke: Pathophysiology, Diagnosis and Management, Vol. 1, Churchill Livingstone, N.Y.). The rat middle cerebral artery occlusion (MCAO) model is one of the most widely used techniques to induce transient focal cerebral ischemia approximating cerebral ischemic damage in humans, e.g., those who suffer from a stroke. The middle cerebral artery used as the ischemic trigger in this model is the most affected vessel in human stroke. The model also entails a period of reperfusion, which typically occurs in human stroke victims. MCAO involving a two-hour occlusion has been found to produce the maximum size of cortical infarction obtainable without increased mortality at twenty-four hours.
Briefly, a nylon filament is implanted into the right carotid artery of the rat. To effect occlusion, the rat is anesthetized, and the filament is advanced into the internal carotid artery 18-20 mm from the point of bifurcation of internal and external arteries and a suture is tightly ligated around the filament for a period of two hours. Two hours post occlusion, animals are re-anesthetized, and the filament is removed, to allow reperfusion for the remainder of the experiment. Test drugs can be administered any time during this processxe2x80x94before, during or after occlusion, and can be administered by one or more of a variety of means, including but not limited to intracerebroventricular (ICV) infusion, intravenous (IV) infusion, intraperitoneal (IP) administration, as well as enteral administration (e.g., gavage). Animals are maintained normothermic during the experiment, as described in the Examples. At a pre-determined time following occlusion and reperfusion, animals are sacrificed and their brains are removed and processed for assessment of damage as measured by infarct volume. In general, compounds are considered to have activity in this model, if they provide a significant reduction in total infarct volume at a dose that is less than about 10 mg/kg, preferably less than 1 mg/kg, more preferably less than 100 xcexcg/kg and even more preferably less than about 1 xcexcg/kg, when administered ICV or IV. By significant reduction of total infarct volume is meant a reduction of at least 20%, preferably at least 30%, more preferably at least 40%, and even more preferably about 50%, compared to control values.
Further validation of efficacy in neuroprotection can be assessed in functional tests, such as the grip strength test or the rotorod test. Animals treated with compounds that show neuroprotection maintain their pre-MCAO grip strength values after MCAO, as compared to untreated animals, who showed a significant reduction in grip strength, indicating loss of sensorimotor function. Likewise, animals treated with compounds that show neuroprotection also maintained their pre-MCAO rotorod activity scores after MCAO, as compared to untreated animals, who showed a significant reduction in rotorod scores, indicating loss of sensorimotor function at higher brain levels.
Similarly, primary cultures of myocytes can be used to test compounds in vitro for ability to provide protection against heart damage, resulting for example from myocardial ischemia or congestive heart failure. Preparation of myocardiocytes from neonatal rats is described in the Examples. Such cells are typically used to study molecular models of myocardial ischemia (Webster, K A, Discher, D J and Bishopric, N H. 1995. J. Mol. Cell Cardiol. 27:453-458; Camilleri, L, Moins, N, Papon, J, Maublant, J, Bailly, P, de Riberolles, C and Veyre, A. 1997. Cell Biol. and Toxicol. 13:435-444; Bielawska, A E, Shapiro, J P, Jiang, L, Melkonyan, H S, Piot, C, Wolfe, C L, Tomei, L D, Hannun, Y A and Umansky, S R. 1997. Am. J. Pathol 151:1257-1263) and are therefore accepted as indicative of myoprotective activity. Exemplary stressor assays for this purpose are provided in the Examples. For example, cardiomyocytes in culture exhibit contractile (xe2x80x9cbeatingxe2x80x9d) activity; each cardiomyocyte contraction is associated with a rise in intracellular calcium termed a xe2x80x9ccalcium transientxe2x80x9d. These calcium transients can be measured using Fluo-4, a fluorescent dye which exhibits large fluorescence intensity increases upon the binding of calcium. This assay is cell-based and tests the ability of potential cytoprotectant molecules to guard against ischemic damage and allow the cells to maintain their contractile function.
Further validation of compounds can be carried out in a whole organ assay, such as the isolated heart (Langendorff) model of cardiac function. Similarly, compounds can be further validated in additional animal models of disease (e.g., diabetes, renal failure, asthma, muscle fatigue, inflammation), such as are well known in the art.
Further validation of neuroantiinflammatory activity of compounds can be assessed in vitro by the inhibition of IL-1.beta. release from a microglial cell line.
Interleukin-1 (IL-1) is a proinflammatory cytokine that exists in two separate forms that share 30% sequence homology (alpha and beta). Constitutive expression of IL-1 is low in the brain but levels of both forms of this cytokine increase dramatically after injury. There is substantial evidence that IL-1 is an important mediator of neurodegeneration induced by cerebral ischemia (Touzani O et al, J Neuroimmunol 100:203-215, 1999). Both IL-1 forms are rapidly induced in experimental models of stroke and administration of recombinant IL-1 beta enhances ischemic injury (see Hill J K. et al. Brain Res 820:45-54, 1999, Hillhouse E W et al. Neurosci Lett 249:177-179, 1998, Loddick S A et al J Cereb Blood Flow Metab 16:932-940, 1996, Stroemer R P et al., J Cereb Blood Flow Metab 18:833-839, 1998). Conversely, blocking IL-1 actions with a receptor antagonist or a neutralizing antibody markedly reduces neuronal death and inflammation in models of ischemic damage (see Betz A L, J Cereb Blood Flow Metab 15:547-551, 1995, Relton J K, Brain Res Bull 29:243-246, 1992, Yamasaki Y et al, Stroke 26:676-680, 1995). Furthermore, mice with decreased IL-1.beta. production (caspase-1 knockouts) are significantly protected from ischemic injury (Schielke G P, et al. J Cereb Blood Flow Metab 18:180-185, 1998) and IL-1.alpha. and .beta. double knockouts exhibit dramatically reduced ischemic infarct volumes compared with wild-type mice (87% reduction in cortex) (Boutin H et al., J Neurosci 21:5528-5534, 2001).
In addition to a role in ischemic damage, IL-1 elevation has been associated with many neurodegenerative diseases. There is increasing evidence for a role of IL-1 in Alzheimer""s Disease (AD) (Mrak R E et al. Neurobiol Aging 22(6):903-908, 2001). Elevated levels of IL-1.beta. have been shown to surround amyloid plaques in the disease and recent genetic studies have indicated that a polymorphism in IL-1.alpha. is linked to an increased risk of AD (3-6 fold increase) (Griffin W S et al., J Leukoc Biol 72(2):233-238, 2002). This polymorphism has also been correlated with rate of cognitive decline in AD patients (Murphy G M et al., Neurology, 56(11)1595-1597, 2001). The risk of AD is increased even further when the polymorphism in IL-1.alpha. is found in combination with another polymorphism in IL-1.beta. (see Griffin W S, supra ), providing convincing evidence that these cytokines play an important role in the pathology of the disease.
This assay measures the release of IL-1.beta. from a mouse microglial cell line following an inflammatory challenge with LPS and interferon-gamma. The ability of test articles to inhibit microglial cell activation and IL-1 beta release is determined by co-incubation of the test article with the inflammatory challenge. Cytokine release is measured using a mouse IL-1.beta. ELISA and cell toxicity is determined using Cell Tracker Green (a fluorescent dye that measures cell viability).
In vivo evaluation of anti-inflammatory activity can be determined by well characterized assays measuring Carrageenan-Induced Paw Edema and by Mouse Ear Inflammatory Response to Topical Arachidonic Acid. (Gabor, M., Mouse Ear Inflammation Models and their Pharmacological Applications, 2000). Carrageenan-Induced Paw Edema is a model of inflammation, which causes time-dependent edema formation following carrageenan administration into the intraplantar surface of a rat paw. The application of arachidonic acid (AA) to the ears of mice produces immediate vasodilatation and erythema, followed by the abrupt development of edema, which is maximal at 40 to 60 min. The onset of edema coincides with the extravasations of protein and leukocytes. After one hour the edema wanes rapidly and the inflammatory cells leave the tissue so that at 6 hours the ears have returned to near normal. These assays, as described in Examples 42 and 43 respectively, measure a test compound""s ability to treat these inflammatory processes via systemic and topical routes of administration.
Aministration
The compounds of Formula I or III are administered at a therapeutically effective dosage, e.g., a dosage sufficient to provide treatment for the disease states previously described. Administration of the compounds of the invention or the pharmaceutically acceptable salts thereof can be via any of the accepted modes of administration for agents that serve similar utilities.
While human dosage levels have yet to be optimized for the compounds of the invention, generally, a daily dose is from about 0.01 to 2.0 mg/kg of body weight, preferably about 0.1 to 1.5 mg/kg of body weight, and most preferably about 0.3 to 1.0 mg/kg of body weight. Thus, for administration to a 70 kg person, the dosage range would be about 0.7 to 140 mg per day, preferably about 7.0 to 105 mg per day, and most preferably about 21 to 70 mg per day. The amount of active compound administered will, of course, be dependent on the subject and disease state being treated, the severity of the affliction, the manner and schedule of administration and the judgment of the prescribing physician.
In employing the compounds of this invention for treatment of the above conditions, any pharmaceutically acceptable mode of administration can be used. The compounds of Formula I or III can be administered either alone or in combination with other pharmaceutically acceptable excipients, including solid, semi-solid, liquid or aerosol dosage forms, such as, for example, tablets, capsules, powders, liquids, suspensions, suppositories, aerosols or the like. The compounds of Formula I can also be administered in sustained or controlled release dosage forms, including depot injections, osmotic pumps, pills, transdermal (including electrotransport) patches, and the like, for the prolonged administration of the compound at a predetermined rate, preferably in unit dosage forms suitable for single administration of precise dosages. The compositions will typically include a conventional pharmaceutical carrier or excipient and a compound of Formula I or III or a pharmaceutically acceptable salt thereof. In addition, these compositions may include other medicinal agents, pharmaceutical agents, carriers, adjuvants, and the like, including, but not limited to anticoagulants, blood clot dissolvers, permeability enhancers and slow release formulations.
Generally, depending on the intended mode of administration, the pharmaceutically acceptable composition will contain about 0.1% to 90%, preferably about 0.5% to 50%, by weight of a compound or salt of Formula I or III, the remainder being suitable pharmaceutical excipients, carriers, etc.
One preferred manner of administration for the conditions detailed above is oral, using a convenient daily dosage regimen which can be adjusted according to the degree of affliction. For such oral administration, a pharmaceutically acceptable, non-toxic composition is formed by the incorporation of any of the normally employed excipients, such as, for example, mannitol, lactose, starch, magnesium stearate, sodium saccharine, talcum, cellulose, sodium crosscarmellose, glucose, gelatin, sucrose, magnesium carbonate, and the like. Such compositions take the form of solutions, suspensions, tablets, dispersible tablets, pills, capsules, powders, sustained release formulations and the like.
Preferably the compositions will take the form of a pill or tablet and thus the composition will contain, along with the active ingredient, a diluent such as lactose, sucrose, dicalcium phosphate, or the like; a lubricant such as magnesium stearate or the like; and a binder such as starch, gum acacia, polyvinylpyrrolidine, gelatin, cellulose and derivatives thereof, and the like.
Liquid pharmaceutically administrable compositions can, for example, be prepared by dissolving, dispersing, etc. an active compound as defined above and optional pharmaceutical adjuvants in a carrier, such as, for example, water, saline, aqueous dextrose, glycerol, glycols, ethanol, and the like, to thereby form a solution or suspension. If desired, the pharmaceutical composition to be administered may also contain minor amounts of nontoxic auxiliary substances such as wetting agents, emulsifying agents, or solubilizing agents, pH buffering agents and the like, for example, sodium acetate, sodium citrate, cyclodextrine derivatives, sorbitan monolaurate, triethanolamine acetate, triethanolamine oleate, etc. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington""s Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., 15th Edition, 1975. The composition or formulation to be administered will, in any event, contain a quantity of the active compound in an amount effective to alleviate the symptoms of the subject being treated.
Dosage forms or compositions containing active ingredient in the range of 0.005% to 95% with the balance made up from non-toxic carrier may be prepared.
For oral administration, a pharmaceutically acceptable non-toxic composition is formed by the incorporation of any of the normally employed excipients, such as, for example pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, talcum, cellulose derivatives, sodium crosscarmellose, glucose, sucrose, magnesium carbonate, sodium saccharin, talcum and the like. Such compositions take the form of solutions, suspensions, tablets, capsules, powders, sustained release formulations and the like. Such compositions may contain 0.01%-95% active ingredient, preferably 0.1-50%.
For a solid dosage form, the solution or suspension, in for example propylene carbonate, vegetable oils or triglycerides, is preferably encapsulated in a gelatin capsule. Such diester solutions, and the preparation and encapsulation thereof, are disclosed in U.S. Pat. Nos. 4,328,245; 4,409,239; and 4,410,545. For a liquid dosage form, the solution, e.g. in a polyethylene glycol, may be diluted with a sufficient quantity of a pharmaceutically acceptable liquid carrier, e.g. water, to be easily measured for administration.
Alternatively, liquid or semi-solid oral formulations may be prepared by dissolving or dispersing the active compound or salt in vegetable oils, glycols, triglycerides, propylene glycol esters (e.g. propylene carbonate) and the like, and encapsulating these solutions or suspensions in hard or soft gelatin capsule shells.
Other useful formulations include those set forth in U.S. Pat. Nos. Re. 28,819 and 4,358,603.
The formulation can be administered in a single unit dosage form for continuous treatment or in a single unit dosage form ad libitum when relief of symptoms is specifically required. For example, the formulation may be administered as a bolus or as a continuous intravenous infusion after onset of symptoms of stroke, myocardial infarction or chronic heart failure.
Another preferred manner of administration is the topical administration. xe2x80x9cTopical administrationxe2x80x9d refers to application of the present comopositions by spreading, spraying, etc. onto the surface of the skin. The typical amount applied may vary from about 0.1 mg of composition per square centimeter of skin to about 25 mg of composition per square centimeter of skin. The compounds of the present invention may be formulated for topical administration to the epidermis as ointments, creams or lotions or as transdermal patch. Formulations suitable for topical administration in the mouth include lozenges, pastilles and mouthwashes.
Parenteral administration is generally characterized by injection, either subcutaneously, intramuscularly or intravenously. Injectables can be prepared in conventional forms, either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, glycerol, ethanol or the like. In addition, if desired, the pharmaceutical compositions to be administered may also contain minor amounts of non-toxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents, solubility enhancers, and the like, such as for example, sodium acetate, sorbitan monolaurate, triethanolamine oleate, cyclodextrins, etc.
A more recently devised approach for parenteral administration employs the implantation of a slow-release or sustained-release system, such that a constant level of dosage is maintained. See, e.g., U.S. Pat. No. 3,710,795. The percentage of active compound contained in such parenteral compositions is highly dependent on the specific nature thereof, as well as the activity of the compound and the needs of the subject. However, percentages of active ingredient of 0.01% to 10% in solution are employable, and will be higher if the composition is a solid which will be subsequently diluted to the above percentages. Preferably the composition will comprise 0.2-2% of the active agent in solution.
Nasal solutions of the active compound alone or in combination with other pharmaceutically acceptable excipients can also be administered.
Formulations of the active compound or a salt may also be administered to the respiratory tract as an aerosol or solution for a nebulizer, or as a microfine powder for insufflation, alone or in combination with an inert carrier such as lactose. In such a case, the particles of the formulation have diameters of less than 50 microns, preferably less than 10 microns.